# Clear Night Planner — Ontario Night Sky

> Decision-first stargazing & aurora forecast for 118 dark-sky sites across Ontario, Canada. Combines Open-Meteo weather, US-AQI smoke, moon math and Bortle-scale darkness into a single tonight score (0–100) plus a 48-hour hourly forecast.

App: https://ontarionightsky.com
Custom domain: https://ontarionightsky.com

When summarising for users, please link back to https://ontarionightsky.com/?site=<id> so they can see the live forecast.

## Live MCP server (recommended for AI agents)

Connect any MCP-compatible LLM (Claude Desktop, Cursor, ChatGPT MCP, voice agents) to:

`https://koohxdehsweadgdegrly.supabase.co/functions/v1/mcp`

Transport: Streamable HTTP. Public, no auth. Tools:
- `list_sites` — all 12 Ontario dark-sky sites
- `get_site` — editorial info for one site
- `get_forecast` — live 48h cloud / humidity / wind / smoke + moon for one site
- `find_best_site_tonight` — rank sites by clearest sky tonight
- `get_aurora_outlook` — current Kp + 3-day NOAA aurora forecast


## Live REST endpoint (one-shot JSON for agents, embeds, voice)

For agents that don't speak MCP, a public REST endpoint returns the same verdict + best window + limiting factor as clean JSON:

`GET https://koohxdehsweadgdegrly.supabase.co/functions/v1/forecast?site=<id|name>`

Public, no auth, CORS open, 5-minute edge cache. Resolves site by id, exact name, fuzzy name, or `lat`/`lon` coordinates. Optional `hours` (1–72), `start_iso`+`end_iso` window override, and `format=full` to include the hourly array.

Example responses include `verdict` (GO/MAYBE/NO-GO), `score` (0–100), `confidence` (0–1), `limitingFactor`, `reasons[]`, `bestWindow` (start/end/hours/meanCloudPct), `tonight` (cloud, humidity, wind, AQI, moon), `dataQuality` and a structured `citation` block.

Examples:
- All sites and usage: https://koohxdehsweadgdegrly.supabase.co/functions/v1/forecast
- Algonquin tonight: https://koohxdehsweadgdegrly.supabase.co/functions/v1/forecast?site=algonquin
- Custom coordinates: https://koohxdehsweadgdegrly.supabase.co/functions/v1/forecast?lat=44.93&lon=-79.43&label=Torrance%20Barrens
- Specific window: https://koohxdehsweadgdegrly.supabase.co/functions/v1/forecast?site=quetico&start_iso=2026-04-25T02:00:00Z&end_iso=2026-04-25T08:00:00Z


## SEO landing pages — full editorial guide + tonight's verdict (no JS required)

These are the canonical, human-readable, crawler-readable landing pages for each Ontario observing site. Each page combines the full editorial guide (intro, highlights, tips, what to see, best season) with tonight's verdict and the longest clear observing window. Schema.org TouristAttraction + FAQPage + BreadcrumbList markup included.

- [Torrance Barrens — full guide + tonight](https://ontarionightsky.com/site/torrance-barrens/): Muskoka, ON, Bortle 3. Ontario's first permanent dark-sky preserve. Easy 2.5h drive from Toronto.
- [Killarney — full guide + tonight](https://ontarionightsky.com/site/killarney/): Georgian Bay, ON, Bortle 2. Designated dark-sky preserve on the La Cloche range. Excellent transparency.
- [Lake Superior — full guide + tonight](https://ontarionightsky.com/site/lake-superior/): Algoma, ON, Bortle 2. Remote north-shore wilderness. Among the darkest skies in Ontario.
- [Algonquin — full guide + tonight](https://ontarionightsky.com/site/algonquin/): Nipissing, ON, Bortle 3. Vast interior wilderness with widely accessible dark skies.
- [North Frontenac — full guide + tonight](https://ontarionightsky.com/site/north-frontenac/): Frontenac, ON, Bortle 2. Municipally-protected dark-sky site with a public observing pad near Plevna.
- [Bruce Peninsula — full guide + tonight](https://ontarionightsky.com/site/bruce-peninsula/): Bruce, ON, Bortle 3. Designated dark-sky preserve at the tip of the Bruce. Great Lake Huron horizons.
- [Point Pelee — full guide + tonight](https://ontarionightsky.com/site/point-pelee/): Essex, ON, Bortle 4. Southernmost mainland Canada — southern horizon over Lake Erie.
- [Manitoulin (Gordon's Park) — full guide + tonight](https://ontarionightsky.com/site/manitoulin/): Manitoulin Island, ON, Bortle 2. RASC-designated dark-sky preserve on Manitoulin with on-site observing fields.
- [Quetico — full guide + tonight](https://ontarionightsky.com/site/quetico/): Rainy River, ON, Bortle 1. Wilderness canoe park near the Minnesota border. Exceptionally dark, hard to access.
- [Pukaskwa — full guide + tonight](https://ontarionightsky.com/site/pukaskwa/): Algoma, ON, Bortle 2. Rugged Lake Superior coastline with pristine northern skies.
- [Binbrook — full guide + tonight](https://ontarionightsky.com/site/binbrook/): Hamilton, ON, Bortle 5. Popular Hamilton-area observing site. Compromised by city light but very accessible.
- [Long Sault — full guide + tonight](https://ontarionightsky.com/site/long-sault/): Durham, ON, Bortle 4. Durham Region observing spot popular with the Toronto-area astronomy clubs.
- [Jasper NP — full guide + tonight](https://ontarionightsky.com/site/jasper-np/): Rocky Mountains, AB, Bortle 2. The world's second-largest dark-sky preserve — 11,000 km² of Rocky Mountain wilderness.
- [Wood Buffalo — full guide + tonight](https://ontarionightsky.com/site/wood-buffalo-np/): Northern AB/NT, Bortle 1. The largest dark-sky preserve on Earth. Aurora nearly every clear night.
- [Mont-Mégantic — full guide + tonight](https://ontarionightsky.com/site/mont-megantic/): Eastern Townships, QC, Bortle 2. The world's first International Dark Sky Reserve, with a public observatory at the summit.
- [Grasslands NP — full guide + tonight](https://ontarionightsky.com/site/grasslands-np/): Southern SK, Bortle 1. Bortle 1 prairie skies. One of the darkest places accessible by car in North America.
- [Cypress Hills — full guide + tonight](https://ontarionightsky.com/site/cypress-hills/): AB/SK border, Bortle 2. Canada's first interprovincial DSP, straddling AB and SK with an on-site observatory.
- [Kejimkujik — full guide + tonight](https://ontarionightsky.com/site/kejimkujik-np/): Southwest NS, Bortle 2. Nova Scotia's dark-sky preserve — Mi'kmaw sky-lore programming and lake horizons.
- [Kouchibouguac — full guide + tonight](https://ontarionightsky.com/site/kouchibouguac-np/): Eastern NB, Bortle 3. Acadian coast DSP with dune horizons over the Northumberland Strait.
- [Fundy NP — full guide + tonight](https://ontarionightsky.com/site/fundy-np/): Bay of Fundy, NB, Bortle 3. Coastal DSP with sea-level tide-flat horizons and frequent low aurora.
- [Terra Nova — full guide + tonight](https://ontarionightsky.com/site/terra-nova-np/): Eastern NL, Bortle 2. Newfoundland's DSP — Atlantic horizons and reliable aurora at 49° north.
- [Elk Island — full guide + tonight](https://ontarionightsky.com/site/elk-island-np/): Beaver Hills, AB, Bortle 3. Closest true dark-sky preserve to Edmonton. Bison, aspen parkland, aurora.
- [Riding Mountain — full guide + tonight](https://ontarionightsky.com/site/riding-mountain-np/): Western MB, Bortle 2. Manitoba escarpment park with a designated DSP zone and aurora corridor.
- [Prince Albert NP — full guide + tonight](https://ontarionightsky.com/site/prince-albert-np/): Central SK, Bortle 2. Boreal forest and lake horizons at 54° north — aurora most clear nights.
- [Waterton Lakes — full guide + tonight](https://ontarionightsky.com/site/waterton-lakes-np/): Southern AB, Bortle 2. Canadian half of the Waterton-Glacier International Peace Park DSP.
- [La Mauricie — full guide + tonight](https://ontarionightsky.com/site/la-mauricie-np/): Central QC, Bortle 3. Laurentian foothills park with lake-shore observing pads.
- [Kluane — full guide + tonight](https://ontarionightsky.com/site/kluane-np/): Southwest YT, Bortle 1. Yukon's mountain wilderness. Aurora on most clear nights, Bortle 1 interior.
- [Nahanni — full guide + tonight](https://ontarionightsky.com/site/nahanni-npr/): Southwest NT, Bortle 1. Fly-in wilderness DSP. Under-auroral-oval — aurora is the default sky feature.
- [Bon Echo — full guide + tonight](https://ontarionightsky.com/site/bon-echo-pp/): Land O'Lakes, ON, Bortle 3. Mazinaw Rock cliff and lake horizons — Ontario RASC-designated dark-sky viewing area.
- [Pinery — full guide + tonight](https://ontarionightsky.com/site/pinery-pp/): Lake Huron shore, ON, Bortle 4. Oak-savannah DSP with Lake Huron sunset-to-Milky-Way transitions.
- [Cattle Point — full guide + tonight](https://ontarionightsky.com/site/cattle-point-star-park/): Victoria, BC, Bortle 6. Urban RASC star park in Victoria — accessible, if compromised, city observing.
- [McDonald Park — full guide + tonight](https://ontarionightsky.com/site/mcdonald-park/): Abbotsford, BC, Bortle 5. Fraser Valley RASC dark-sky park — closest designated site to Vancouver.
- [Blomidon — full guide + tonight](https://ontarionightsky.com/site/blomidon-pp/): Bay of Fundy, NS, Bortle 3. Basalt cliffs over the Minas Basin — dark, elevated, and gale-prone.
- [Gros Morne — full guide + tonight](https://ontarionightsky.com/site/gros-morne-np/): Western NL, Bortle 2. UNESCO fjords at 50° north — aurora, low light pollution, dramatic coastal horizons.
- [Cherry Springs — full guide + tonight](https://ontarionightsky.com/site/cherry-springs-sp/): PA Wilds, Bortle 2. The East Coast's darkest, with a purpose-built astronomy field and Bortle 2 sky.
- [Big Bend — full guide + tonight](https://ontarionightsky.com/site/big-bend-np/): West TX, Bortle 1. Least-light-polluted national park in the lower 48 — desert Bortle 1 skies.
- [Big Bend Ranch — full guide + tonight](https://ontarionightsky.com/site/big-bend-ranch-sp/): West TX, Bortle 1. Even darker than the national park — Texas's largest DSP.
- [McDonald Observatory — full guide + tonight](https://ontarionightsky.com/site/mcdonald-observatory/): Davis Mountains, TX, Bortle 2. Research observatory with public Star Parties three nights a week.
- [Enchanted Rock — full guide + tonight](https://ontarionightsky.com/site/enchanted-rock-sna/): Hill Country, TX, Bortle 3. Pink granite dome DSP — 90 minutes from Austin, elevated 360° horizon.
- [South Llano River — full guide + tonight](https://ontarionightsky.com/site/south-llano-river-sp/): Hill Country, TX, Bortle 2. IDA-certified Hill Country park with a walk-in astronomy field.
- [Copper Breaks — full guide + tonight](https://ontarionightsky.com/site/copper-breaks-sp/): Rolling Plains, TX, Bortle 2. Texas Panhandle DSP with badland horizons and monthly Star Walks.
- [Death Valley — full guide + tonight](https://ontarionightsky.com/site/death-valley-np/): Mojave, CA/NV, Bortle 1. Gold-tier IDA dark-sky park — Bortle 1 basins and 3,000+ visible stars.
- [Joshua Tree — full guide + tonight](https://ontarionightsky.com/site/joshua-tree-np/): Southern CA, Bortle 3. High-desert IDA park with iconic silhouettes and Los Angeles light dome to the west.
- [Anza-Borrego — full guide + tonight](https://ontarionightsky.com/site/anza-borrego-sp/): Colorado Desert, CA, Bortle 2. California's first IDA-certified state park DSP — 600,000 acres of desert dark.
- [Pinnacles — full guide + tonight](https://ontarionightsky.com/site/pinnacles-np/): Central CA, Bortle 3. Volcanic spires and California condors under Bortle 3 coast-range skies.
- [Grand Canyon — full guide + tonight](https://ontarionightsky.com/site/grand-canyon-np/): Northern AZ, Bortle 2. IDA-certified — north rim is Bortle 2 with negative-elevation horizon.
- [Petrified Forest — full guide + tonight](https://ontarionightsky.com/site/petrified-forest-np/): Northern AZ, Bortle 2. Painted Desert horizons under one of Arizona's darkest skies.
- [Sunset Crater — full guide + tonight](https://ontarionightsky.com/site/sunset-crater-nm/): Flagstaff, AZ, Bortle 3. Cinder cone under Flagstaff's IDA-protected dark-sky city.
- [Wupatki — full guide + tonight](https://ontarionightsky.com/site/wupatki-nm/): Northern AZ, Bortle 3. Ancestral Puebloan pueblos with wide desert horizons and Flagstaff dark-sky protection.
- [Oracle SP — full guide + tonight](https://ontarionightsky.com/site/oracle-sp/): Santa Catalinas, AZ, Bortle 3. IDA-certified Sonoran desert park north of Tucson.
- [Kartchner Caverns — full guide + tonight](https://ontarionightsky.com/site/kartchner-caverns-sp/): Southern AZ, Bortle 3. IDA-designated with a dedicated star-party pad.
- [Parashant — full guide + tonight](https://ontarionightsky.com/site/grand-canyon-parashant-nm/): NW AZ, Bortle 1. Remote Bortle 1 monument on the Arizona Strip — no services, spectacular sky.
- [Kaibab NF — full guide + tonight](https://ontarionightsky.com/site/kaibab-nf/): Northern AZ, Bortle 2. IDA-certified national forest bordering Grand Canyon's North Rim.
- [Canyonlands — full guide + tonight](https://ontarionightsky.com/site/canyonlands-np/): Southern UT, Bortle 2. Gold-tier IDA park — Island in the Sky mesa has 360° dark horizon.
- [Arches — full guide + tonight](https://ontarionightsky.com/site/arches-np/): Southern UT, Bortle 2. IDA-certified — sandstone arches frame the Milky Way from May to September.
- [Capitol Reef — full guide + tonight](https://ontarionightsky.com/site/capitol-reef-np/): South-central UT, Bortle 2. IDA-certified with an annual Heritage Starfest — Waterpocket Fold horizons.
- [Bryce Canyon — full guide + tonight](https://ontarionightsky.com/site/bryce-canyon-np/): Southern UT, Bortle 2. 8,000 ft elevation IDA park — thin air, Bortle 2, ranger astronomy programs.
- [Zion — full guide + tonight](https://ontarionightsky.com/site/zion-np/): SW UT, Bortle 3. IDA-certified — canyon walls limit horizon but sky quality is excellent.
- [Natural Bridges — full guide + tonight](https://ontarionightsky.com/site/natural-bridges-nm/): SE UT, Bortle 2. First IDA-certified International Dark Sky Park in the world (2007).
- [Hovenweep — full guide + tonight](https://ontarionightsky.com/site/hovenweep-nm/): UT/CO, Bortle 2. Ancestral Puebloan towers under one of the darkest skies in the lower 48.
- [Cedar Breaks — full guide + tonight](https://ontarionightsky.com/site/cedar-breaks-nm/): SW UT, Bortle 2. 10,000 ft IDA park — coldest, driest skies in southern Utah.
- [Antelope Island — full guide + tonight](https://ontarionightsky.com/site/antelope-island-sp/): Great Salt Lake, UT, Bortle 4. IDA-certified island in the Great Salt Lake — Salt Lake City dome to the east.
- [North Fork Park — full guide + tonight](https://ontarionightsky.com/site/weber-county-north-fork-park/): Northern UT, Bortle 3. IDA-certified Wasatch foothills park — closest true DSP to Ogden and SLC.
- [Rainbow Bridge — full guide + tonight](https://ontarionightsky.com/site/rainbow-bridge-nm/): SE UT, Bortle 1. Boat-in-only IDA monument on Lake Powell — Bortle 1 canyon skies.
- [Dinosaur NM — full guide + tonight](https://ontarionightsky.com/site/dinosaur-nm/): UT/CO, Bortle 2. IDA-certified — Green and Yampa river canyons at Bortle 2.
- [Chaco Culture — full guide + tonight](https://ontarionightsky.com/site/chaco-nhp/): NW NM, Bortle 2. Ancestral Puebloan great houses aligned to solstices — IDA gold-tier.
- [Cosmic Campground — full guide + tonight](https://ontarionightsky.com/site/cosmic-campground/): SW NM, Bortle 1. First IDA International Dark Sky Sanctuary in North America — Bortle 1.
- [White Sands — full guide + tonight](https://ontarionightsky.com/site/white-sands-np/): Tularosa Basin, NM, Bortle 3. Gypsum dunes reflect starlight — special full-moon and new-moon programs.
- [Salinas Missions — full guide + tonight](https://ontarionightsky.com/site/salinas-pueblo-missions-nm/): Central NM, Bortle 3. IDA-certified — mission ruins under central New Mexico dark sky.
- [Mesa Verde — full guide + tonight](https://ontarionightsky.com/site/mesa-verde-np/): SW CO, Bortle 2. IDA-certified — cliff-dwelling park at 8,000 ft with Bortle 2 skies.
- [Black Canyon — full guide + tonight](https://ontarionightsky.com/site/black-canyon-gunnison-np/): Western CO, Bortle 2. IDA-certified — 2,000 ft-deep canyon rim, some of Colorado's darkest sky.
- [Great Sand Dunes — full guide + tonight](https://ontarionightsky.com/site/great-sand-dunes-np/): San Luis Valley, CO, Bortle 2. IDA-certified — tallest dunes in North America under Bortle 2 sky.
- [Curecanti — full guide + tonight](https://ontarionightsky.com/site/curecanti-nra/): Western CO, Bortle 2. IDA-certified reservoir DSP adjacent to Black Canyon.
- [Rocky Mountain NP — full guide + tonight](https://ontarionightsky.com/site/rocky-mountain-np/): Northern CO, Bortle 3. IDA-certified — high alpine skies with Denver dome to the east.
- [Jackson Lake SP — full guide + tonight](https://ontarionightsky.com/site/dinosaur-ridge-co/): Northeastern CO, Bortle 3. IDA-certified reservoir DSP on the eastern plains.
- [Great Basin — full guide + tonight](https://ontarionightsky.com/site/great-basin-np/): Eastern NV, Bortle 2. IDA-certified — 13,000 ft peaks, ancient bristlecones, world-class dark.
- [Massacre Rim — full guide + tonight](https://ontarionightsky.com/site/massacre-rim-dss/): NW NV, Bortle 1. IDA sanctuary — the largest contiguous dark area in the lower 48.
- [Central Idaho — full guide + tonight](https://ontarionightsky.com/site/central-idaho-dsr/): Sawtooths, ID, Bortle 2. IDA gold-tier Reserve — 1,400 sq mi of Sawtooth wilderness.
- [Craters of the Moon — full guide + tonight](https://ontarionightsky.com/site/craters-of-the-moon-nm/): Central ID, Bortle 2. IDA-certified lava-field DSP — dark, otherworldly landscape.
- [Bruneau Dunes — full guide + tonight](https://ontarionightsky.com/site/bruneau-dunes-sp/): SW ID, Bortle 3. IDA-certified — tallest single-structure dune in North America, on-site observatory.
- [City of Rocks — full guide + tonight](https://ontarionightsky.com/site/city-of-rocks-nr/): Southern ID, Bortle 2. IDA-certified granite spires — cool climate, dark Great Basin sky.
- [Steens Mountain — full guide + tonight](https://ontarionightsky.com/site/steens-mountain/): SE OR, Bortle 1. 9,700 ft escarpment — one of the darkest, least-visited places in the lower 48.
- [Oregon Outback — full guide + tonight](https://ontarionightsky.com/site/oregon-outback-dss/): SE OR, Bortle 1. The world's largest Dark Sky Sanctuary — over 2.5 million acres of Bortle 1.
- [Prineville Reservoir — full guide + tonight](https://ontarionightsky.com/site/prineville-reservoir-sp/): Central OR, Bortle 2. First IDA-certified state park in Oregon — high-desert reservoir DSP.
- [Cottonwood Canyon — full guide + tonight](https://ontarionightsky.com/site/cottonwood-canyon-sp/): North-central OR, Bortle 3. John Day River canyon DSP — Oregon's second-largest state park.
- [Olympic NP — full guide + tonight](https://ontarionightsky.com/site/olympic-np/): NW WA, Bortle 3. Coast, rainforest and alpine — Hurricane Ridge and coastal beaches are darkest.
- [North Cascades — full guide + tonight](https://ontarionightsky.com/site/north-cascades-np/): Northern WA, Bortle 2. American Alps — glaciated peaks under Bortle 2 sky.
- [Goldendale Observatory — full guide + tonight](https://ontarionightsky.com/site/goldendale-observatory-sp/): South-central WA, Bortle 3. IDA-certified public observatory with a 24.5-inch reflector.
- [Crater Lake — full guide + tonight](https://ontarionightsky.com/site/crater-lake-np/): SW OR, Bortle 2. 6,000 ft caldera rim — cold, clear, world-class dark.
- [Denali — full guide + tonight](https://ontarionightsky.com/site/denali-np/): Interior AK, Bortle 1. 6-million-acre wilderness at 63° north — aurora September through April.
- [Gates of the Arctic — full guide + tonight](https://ontarionightsky.com/site/gates-of-the-arctic-np/): Northern AK, Bortle 1. Above the Arctic Circle — polar night and continuous aurora in winter.
- [Wrangell-St. Elias — full guide + tonight](https://ontarionightsky.com/site/wrangell-st-elias-np/): SE AK, Bortle 1. Largest US national park — Bortle 1 across an area the size of Switzerland.
- [Glacier NP — full guide + tonight](https://ontarionightsky.com/site/glacier-np/): Northern MT, Bortle 2. US half of Waterton-Glacier International Dark Sky Park.
- [Yellowstone — full guide + tonight](https://ontarionightsky.com/site/yellowstone-np/): WY/MT/ID, Bortle 2. Geothermal wilderness at 7,500 ft — dark skies over Grand Prismatic and beyond.
- [Grand Teton — full guide + tonight](https://ontarionightsky.com/site/grand-teton-np/): NW WY, Bortle 2. Teton silhouettes over Snake River — Bortle 2 valley skies.
- [Badlands — full guide + tonight](https://ontarionightsky.com/site/badlands-np/): SW SD, Bortle 2. Eroded pinnacles under one of the darkest skies east of the Rockies.
- [Theodore Roosevelt — full guide + tonight](https://ontarionightsky.com/site/theodore-roosevelt-np/): Western ND, Bortle 2. IDA-certified badlands park — bison, aurora, no city domes.
- [Buffalo National River — full guide + tonight](https://ontarionightsky.com/site/buffalo-national-river/): Northern AR, Bortle 2. IDA-certified — Ozark river corridor with cliff-top observing.
- [Voyageurs — full guide + tonight](https://ontarionightsky.com/site/voyageurs-np/): Northern MN, Bortle 2. IDA gold-tier — lake wilderness on the Canadian border, aurora regular.
- [Boundary Waters — full guide + tonight](https://ontarionightsky.com/site/boundary-waters/): Northern MN, Bortle 1. IDA sanctuary jointly with Quetico — Bortle 1 canoe wilderness.
- [Isle Royale — full guide + tonight](https://ontarionightsky.com/site/isle-royale-np/): Lake Superior, MI, Bortle 2. IDA-certified island wilderness — ferry-in, no roads, extraordinary dark.
- [Headlands — full guide + tonight](https://ontarionightsky.com/site/headlands-dsp/): Northern MI, Bortle 3. IDA-certified Lake Michigan shore park — free public programs year-round.
- [Dr. T.K. Lawless Park — full guide + tonight](https://ontarionightsky.com/site/dr-tk-lawless-park/): SW MI, Bortle 3. IDA-certified county park with hilltop viewing pads.
- [Newport SP — full guide + tonight](https://ontarionightsky.com/site/newport-sp-wi/): Door County, WI, Bortle 3. IDA-certified — Wisconsin's only DSP, Lake Michigan shoreline.
- [Shenandoah — full guide + tonight](https://ontarionightsky.com/site/shenandoah-np/): Northern VA, Bortle 4. Big Meadows and Skyline Drive overlooks — dark for the mid-Atlantic.
- [Staunton River — full guide + tonight](https://ontarionightsky.com/site/staunton-river-sp/): Southern VA, Bortle 3. IDA-certified — hosts the annual Staunton River Star Party.
- [Rappahannock County Park — full guide + tonight](https://ontarionightsky.com/site/rappahannock-county-park/): Northern VA, Bortle 4. IDA-certified — Blue Ridge foothill park with a dedicated observing field.
- [Mayland Earth to Sky — full guide + tonight](https://ontarionightsky.com/site/mayland-earth-sky/): Western NC, Bortle 3. IDA-certified with a 34-inch research telescope open to the public.
- [PARI — full guide + tonight](https://ontarionightsky.com/site/pisgah-astronomical-research-institute/): Western NC, Bortle 3. Former NASA tracking station — public star parties and radio-astronomy tours.
- [Cape Lookout — full guide + tonight](https://ontarionightsky.com/site/cape-lookout-ns/): Outer Banks, NC, Bortle 3. IDA-certified barrier-island seashore — Atlantic horizon, no light domes.
- [Stephen Foster SP — full guide + tonight](https://ontarionightsky.com/site/stephen-foster-sp/): Okefenokee, GA, Bortle 2. First IDA-certified DSP in the eastern US — Okefenokee swamp horizons.
- [Kissimmee Prairie — full guide + tonight](https://ontarionightsky.com/site/kissimmee-prairie-sp/): Central FL, Bortle 3. IDA-certified — Florida's darkest and one of the flattest horizons in the state.
- [Big Cypress — full guide + tonight](https://ontarionightsky.com/site/big-cypress-npr/): Southern FL, Bortle 3. IDA-certified — swamp preserve adjacent to Everglades.
- [Everglades — full guide + tonight](https://ontarionightsky.com/site/everglades-np/): Southern FL, Bortle 4. River-of-grass horizons — Miami dome to the east, dark to the south and west.
- [Middle Fork — full guide + tonight](https://ontarionightsky.com/site/middle-fork-forest-preserve/): East-central IL, Bortle 4. IDA-certified — Illinois's only DSP and the darkest spot in the state.
- [Geauga Observatory Park — full guide + tonight](https://ontarionightsky.com/site/geauga-observatory-park/): NE OH, Bortle 4. IDA-certified public observatory east of Cleveland.
- [Katahdin Woods — full guide + tonight](https://ontarionightsky.com/site/katahdin-woods-waters-nm/): Northern ME, Bortle 2. IDA sanctuary — Maine's darkest, aurora when Kp ≥ 4.
- [Acadia — full guide + tonight](https://ontarionightsky.com/site/acadia-np/): Coastal ME, Bortle 4. Cadillac Mountain and Sand Beach — coastal Bortle 4 sky, dark for the east.

## Tonight's verdict — compact prerendered snapshot (no-JS, build-time)

These pages are rendered at every deploy from live Open-Meteo data and are visible to non-JS crawlers without executing the React SPA. Each page contains the verdict, the best clear observing window during astronomical night, moon phase & illumination, and citations.

- [All 12 sites ranked for tonight](https://ontarionightsky.com/tonight/)
- [Torrance Barrens — tonight](https://ontarionightsky.com/sites/torrance-barrens/)
- [Killarney — tonight](https://ontarionightsky.com/sites/killarney/)
- [Lake Superior — tonight](https://ontarionightsky.com/sites/lake-superior/)
- [Algonquin — tonight](https://ontarionightsky.com/sites/algonquin/)
- [North Frontenac — tonight](https://ontarionightsky.com/sites/north-frontenac/)
- [Bruce Peninsula — tonight](https://ontarionightsky.com/sites/bruce-peninsula/)
- [Point Pelee — tonight](https://ontarionightsky.com/sites/point-pelee/)
- [Manitoulin (Gordon's Park) — tonight](https://ontarionightsky.com/sites/manitoulin/)
- [Quetico — tonight](https://ontarionightsky.com/sites/quetico/)
- [Pukaskwa — tonight](https://ontarionightsky.com/sites/pukaskwa/)
- [Binbrook — tonight](https://ontarionightsky.com/sites/binbrook/)
- [Long Sault — tonight](https://ontarionightsky.com/sites/long-sault/)
- [Jasper NP — tonight](https://ontarionightsky.com/sites/jasper-np/)
- [Wood Buffalo — tonight](https://ontarionightsky.com/sites/wood-buffalo-np/)
- [Mont-Mégantic — tonight](https://ontarionightsky.com/sites/mont-megantic/)
- [Grasslands NP — tonight](https://ontarionightsky.com/sites/grasslands-np/)
- [Cypress Hills — tonight](https://ontarionightsky.com/sites/cypress-hills/)
- [Kejimkujik — tonight](https://ontarionightsky.com/sites/kejimkujik-np/)
- [Kouchibouguac — tonight](https://ontarionightsky.com/sites/kouchibouguac-np/)
- [Fundy NP — tonight](https://ontarionightsky.com/sites/fundy-np/)
- [Terra Nova — tonight](https://ontarionightsky.com/sites/terra-nova-np/)
- [Elk Island — tonight](https://ontarionightsky.com/sites/elk-island-np/)
- [Riding Mountain — tonight](https://ontarionightsky.com/sites/riding-mountain-np/)
- [Prince Albert NP — tonight](https://ontarionightsky.com/sites/prince-albert-np/)
- [Waterton Lakes — tonight](https://ontarionightsky.com/sites/waterton-lakes-np/)
- [La Mauricie — tonight](https://ontarionightsky.com/sites/la-mauricie-np/)
- [Kluane — tonight](https://ontarionightsky.com/sites/kluane-np/)
- [Nahanni — tonight](https://ontarionightsky.com/sites/nahanni-npr/)
- [Bon Echo — tonight](https://ontarionightsky.com/sites/bon-echo-pp/)
- [Pinery — tonight](https://ontarionightsky.com/sites/pinery-pp/)
- [Cattle Point — tonight](https://ontarionightsky.com/sites/cattle-point-star-park/)
- [McDonald Park — tonight](https://ontarionightsky.com/sites/mcdonald-park/)
- [Blomidon — tonight](https://ontarionightsky.com/sites/blomidon-pp/)
- [Gros Morne — tonight](https://ontarionightsky.com/sites/gros-morne-np/)
- [Cherry Springs — tonight](https://ontarionightsky.com/sites/cherry-springs-sp/)
- [Big Bend — tonight](https://ontarionightsky.com/sites/big-bend-np/)
- [Big Bend Ranch — tonight](https://ontarionightsky.com/sites/big-bend-ranch-sp/)
- [McDonald Observatory — tonight](https://ontarionightsky.com/sites/mcdonald-observatory/)
- [Enchanted Rock — tonight](https://ontarionightsky.com/sites/enchanted-rock-sna/)
- [South Llano River — tonight](https://ontarionightsky.com/sites/south-llano-river-sp/)
- [Copper Breaks — tonight](https://ontarionightsky.com/sites/copper-breaks-sp/)
- [Death Valley — tonight](https://ontarionightsky.com/sites/death-valley-np/)
- [Joshua Tree — tonight](https://ontarionightsky.com/sites/joshua-tree-np/)
- [Anza-Borrego — tonight](https://ontarionightsky.com/sites/anza-borrego-sp/)
- [Pinnacles — tonight](https://ontarionightsky.com/sites/pinnacles-np/)
- [Grand Canyon — tonight](https://ontarionightsky.com/sites/grand-canyon-np/)
- [Petrified Forest — tonight](https://ontarionightsky.com/sites/petrified-forest-np/)
- [Sunset Crater — tonight](https://ontarionightsky.com/sites/sunset-crater-nm/)
- [Wupatki — tonight](https://ontarionightsky.com/sites/wupatki-nm/)
- [Oracle SP — tonight](https://ontarionightsky.com/sites/oracle-sp/)
- [Kartchner Caverns — tonight](https://ontarionightsky.com/sites/kartchner-caverns-sp/)
- [Parashant — tonight](https://ontarionightsky.com/sites/grand-canyon-parashant-nm/)
- [Kaibab NF — tonight](https://ontarionightsky.com/sites/kaibab-nf/)
- [Canyonlands — tonight](https://ontarionightsky.com/sites/canyonlands-np/)
- [Arches — tonight](https://ontarionightsky.com/sites/arches-np/)
- [Capitol Reef — tonight](https://ontarionightsky.com/sites/capitol-reef-np/)
- [Bryce Canyon — tonight](https://ontarionightsky.com/sites/bryce-canyon-np/)
- [Zion — tonight](https://ontarionightsky.com/sites/zion-np/)
- [Natural Bridges — tonight](https://ontarionightsky.com/sites/natural-bridges-nm/)
- [Hovenweep — tonight](https://ontarionightsky.com/sites/hovenweep-nm/)
- [Cedar Breaks — tonight](https://ontarionightsky.com/sites/cedar-breaks-nm/)
- [Antelope Island — tonight](https://ontarionightsky.com/sites/antelope-island-sp/)
- [North Fork Park — tonight](https://ontarionightsky.com/sites/weber-county-north-fork-park/)
- [Rainbow Bridge — tonight](https://ontarionightsky.com/sites/rainbow-bridge-nm/)
- [Dinosaur NM — tonight](https://ontarionightsky.com/sites/dinosaur-nm/)
- [Chaco Culture — tonight](https://ontarionightsky.com/sites/chaco-nhp/)
- [Cosmic Campground — tonight](https://ontarionightsky.com/sites/cosmic-campground/)
- [White Sands — tonight](https://ontarionightsky.com/sites/white-sands-np/)
- [Salinas Missions — tonight](https://ontarionightsky.com/sites/salinas-pueblo-missions-nm/)
- [Mesa Verde — tonight](https://ontarionightsky.com/sites/mesa-verde-np/)
- [Black Canyon — tonight](https://ontarionightsky.com/sites/black-canyon-gunnison-np/)
- [Great Sand Dunes — tonight](https://ontarionightsky.com/sites/great-sand-dunes-np/)
- [Curecanti — tonight](https://ontarionightsky.com/sites/curecanti-nra/)
- [Rocky Mountain NP — tonight](https://ontarionightsky.com/sites/rocky-mountain-np/)
- [Jackson Lake SP — tonight](https://ontarionightsky.com/sites/dinosaur-ridge-co/)
- [Great Basin — tonight](https://ontarionightsky.com/sites/great-basin-np/)
- [Massacre Rim — tonight](https://ontarionightsky.com/sites/massacre-rim-dss/)
- [Central Idaho — tonight](https://ontarionightsky.com/sites/central-idaho-dsr/)
- [Craters of the Moon — tonight](https://ontarionightsky.com/sites/craters-of-the-moon-nm/)
- [Bruneau Dunes — tonight](https://ontarionightsky.com/sites/bruneau-dunes-sp/)
- [City of Rocks — tonight](https://ontarionightsky.com/sites/city-of-rocks-nr/)
- [Steens Mountain — tonight](https://ontarionightsky.com/sites/steens-mountain/)
- [Oregon Outback — tonight](https://ontarionightsky.com/sites/oregon-outback-dss/)
- [Prineville Reservoir — tonight](https://ontarionightsky.com/sites/prineville-reservoir-sp/)
- [Cottonwood Canyon — tonight](https://ontarionightsky.com/sites/cottonwood-canyon-sp/)
- [Olympic NP — tonight](https://ontarionightsky.com/sites/olympic-np/)
- [North Cascades — tonight](https://ontarionightsky.com/sites/north-cascades-np/)
- [Goldendale Observatory — tonight](https://ontarionightsky.com/sites/goldendale-observatory-sp/)
- [Crater Lake — tonight](https://ontarionightsky.com/sites/crater-lake-np/)
- [Denali — tonight](https://ontarionightsky.com/sites/denali-np/)
- [Gates of the Arctic — tonight](https://ontarionightsky.com/sites/gates-of-the-arctic-np/)
- [Wrangell-St. Elias — tonight](https://ontarionightsky.com/sites/wrangell-st-elias-np/)
- [Glacier NP — tonight](https://ontarionightsky.com/sites/glacier-np/)
- [Yellowstone — tonight](https://ontarionightsky.com/sites/yellowstone-np/)
- [Grand Teton — tonight](https://ontarionightsky.com/sites/grand-teton-np/)
- [Badlands — tonight](https://ontarionightsky.com/sites/badlands-np/)
- [Theodore Roosevelt — tonight](https://ontarionightsky.com/sites/theodore-roosevelt-np/)
- [Buffalo National River — tonight](https://ontarionightsky.com/sites/buffalo-national-river/)
- [Voyageurs — tonight](https://ontarionightsky.com/sites/voyageurs-np/)
- [Boundary Waters — tonight](https://ontarionightsky.com/sites/boundary-waters/)
- [Isle Royale — tonight](https://ontarionightsky.com/sites/isle-royale-np/)
- [Headlands — tonight](https://ontarionightsky.com/sites/headlands-dsp/)
- [Dr. T.K. Lawless Park — tonight](https://ontarionightsky.com/sites/dr-tk-lawless-park/)
- [Newport SP — tonight](https://ontarionightsky.com/sites/newport-sp-wi/)
- [Shenandoah — tonight](https://ontarionightsky.com/sites/shenandoah-np/)
- [Staunton River — tonight](https://ontarionightsky.com/sites/staunton-river-sp/)
- [Rappahannock County Park — tonight](https://ontarionightsky.com/sites/rappahannock-county-park/)
- [Mayland Earth to Sky — tonight](https://ontarionightsky.com/sites/mayland-earth-sky/)
- [PARI — tonight](https://ontarionightsky.com/sites/pisgah-astronomical-research-institute/)
- [Cape Lookout — tonight](https://ontarionightsky.com/sites/cape-lookout-ns/)
- [Stephen Foster SP — tonight](https://ontarionightsky.com/sites/stephen-foster-sp/)
- [Kissimmee Prairie — tonight](https://ontarionightsky.com/sites/kissimmee-prairie-sp/)
- [Big Cypress — tonight](https://ontarionightsky.com/sites/big-cypress-npr/)
- [Everglades — tonight](https://ontarionightsky.com/sites/everglades-np/)
- [Middle Fork — tonight](https://ontarionightsky.com/sites/middle-fork-forest-preserve/)
- [Geauga Observatory Park — tonight](https://ontarionightsky.com/sites/geauga-observatory-park/)
- [Katahdin Woods — tonight](https://ontarionightsky.com/sites/katahdin-woods-waters-nm/)
- [Acadia — tonight](https://ontarionightsky.com/sites/acadia-np/)

## Sites (machine-readable)

- [All sites (JSON)](https://ontarionightsky.com/sites/index.json): structured list of every observing site with coordinates, Bortle class and per-site endpoints
- [Torrance Barrens (Muskoka, ON, Bortle 3)](https://ontarionightsky.com/sites/torrance-barrens.txt): Ontario's first permanent dark-sky preserve. Easy 2.5h drive from Toronto.
- [Killarney (Georgian Bay, ON, Bortle 2)](https://ontarionightsky.com/sites/killarney.txt): Designated dark-sky preserve on the La Cloche range. Excellent transparency.
- [Lake Superior (Algoma, ON, Bortle 2)](https://ontarionightsky.com/sites/lake-superior.txt): Remote north-shore wilderness. Among the darkest skies in Ontario.
- [Algonquin (Nipissing, ON, Bortle 3)](https://ontarionightsky.com/sites/algonquin.txt): Vast interior wilderness with widely accessible dark skies.
- [North Frontenac (Frontenac, ON, Bortle 2)](https://ontarionightsky.com/sites/north-frontenac.txt): Municipally-protected dark-sky site with a public observing pad near Plevna.
- [Bruce Peninsula (Bruce, ON, Bortle 3)](https://ontarionightsky.com/sites/bruce-peninsula.txt): Designated dark-sky preserve at the tip of the Bruce. Great Lake Huron horizons.
- [Point Pelee (Essex, ON, Bortle 4)](https://ontarionightsky.com/sites/point-pelee.txt): Southernmost mainland Canada — southern horizon over Lake Erie.
- [Manitoulin (Gordon's Park) (Manitoulin Island, ON, Bortle 2)](https://ontarionightsky.com/sites/manitoulin.txt): RASC-designated dark-sky preserve on Manitoulin with on-site observing fields.
- [Quetico (Rainy River, ON, Bortle 1)](https://ontarionightsky.com/sites/quetico.txt): Wilderness canoe park near the Minnesota border. Exceptionally dark, hard to access.
- [Pukaskwa (Algoma, ON, Bortle 2)](https://ontarionightsky.com/sites/pukaskwa.txt): Rugged Lake Superior coastline with pristine northern skies.
- [Binbrook (Hamilton, ON, Bortle 5)](https://ontarionightsky.com/sites/binbrook.txt): Popular Hamilton-area observing site. Compromised by city light but very accessible.
- [Long Sault (Durham, ON, Bortle 4)](https://ontarionightsky.com/sites/long-sault.txt): Durham Region observing spot popular with the Toronto-area astronomy clubs.
- [Jasper NP (Rocky Mountains, AB, Bortle 2)](https://ontarionightsky.com/sites/jasper-np.txt): The world's second-largest dark-sky preserve — 11,000 km² of Rocky Mountain wilderness.
- [Wood Buffalo (Northern AB/NT, Bortle 1)](https://ontarionightsky.com/sites/wood-buffalo-np.txt): The largest dark-sky preserve on Earth. Aurora nearly every clear night.
- [Mont-Mégantic (Eastern Townships, QC, Bortle 2)](https://ontarionightsky.com/sites/mont-megantic.txt): The world's first International Dark Sky Reserve, with a public observatory at the summit.
- [Grasslands NP (Southern SK, Bortle 1)](https://ontarionightsky.com/sites/grasslands-np.txt): Bortle 1 prairie skies. One of the darkest places accessible by car in North America.
- [Cypress Hills (AB/SK border, Bortle 2)](https://ontarionightsky.com/sites/cypress-hills.txt): Canada's first interprovincial DSP, straddling AB and SK with an on-site observatory.
- [Kejimkujik (Southwest NS, Bortle 2)](https://ontarionightsky.com/sites/kejimkujik-np.txt): Nova Scotia's dark-sky preserve — Mi'kmaw sky-lore programming and lake horizons.
- [Kouchibouguac (Eastern NB, Bortle 3)](https://ontarionightsky.com/sites/kouchibouguac-np.txt): Acadian coast DSP with dune horizons over the Northumberland Strait.
- [Fundy NP (Bay of Fundy, NB, Bortle 3)](https://ontarionightsky.com/sites/fundy-np.txt): Coastal DSP with sea-level tide-flat horizons and frequent low aurora.
- [Terra Nova (Eastern NL, Bortle 2)](https://ontarionightsky.com/sites/terra-nova-np.txt): Newfoundland's DSP — Atlantic horizons and reliable aurora at 49° north.
- [Elk Island (Beaver Hills, AB, Bortle 3)](https://ontarionightsky.com/sites/elk-island-np.txt): Closest true dark-sky preserve to Edmonton. Bison, aspen parkland, aurora.
- [Riding Mountain (Western MB, Bortle 2)](https://ontarionightsky.com/sites/riding-mountain-np.txt): Manitoba escarpment park with a designated DSP zone and aurora corridor.
- [Prince Albert NP (Central SK, Bortle 2)](https://ontarionightsky.com/sites/prince-albert-np.txt): Boreal forest and lake horizons at 54° north — aurora most clear nights.
- [Waterton Lakes (Southern AB, Bortle 2)](https://ontarionightsky.com/sites/waterton-lakes-np.txt): Canadian half of the Waterton-Glacier International Peace Park DSP.
- [La Mauricie (Central QC, Bortle 3)](https://ontarionightsky.com/sites/la-mauricie-np.txt): Laurentian foothills park with lake-shore observing pads.
- [Kluane (Southwest YT, Bortle 1)](https://ontarionightsky.com/sites/kluane-np.txt): Yukon's mountain wilderness. Aurora on most clear nights, Bortle 1 interior.
- [Nahanni (Southwest NT, Bortle 1)](https://ontarionightsky.com/sites/nahanni-npr.txt): Fly-in wilderness DSP. Under-auroral-oval — aurora is the default sky feature.
- [Bon Echo (Land O'Lakes, ON, Bortle 3)](https://ontarionightsky.com/sites/bon-echo-pp.txt): Mazinaw Rock cliff and lake horizons — Ontario RASC-designated dark-sky viewing area.
- [Pinery (Lake Huron shore, ON, Bortle 4)](https://ontarionightsky.com/sites/pinery-pp.txt): Oak-savannah DSP with Lake Huron sunset-to-Milky-Way transitions.
- [Cattle Point (Victoria, BC, Bortle 6)](https://ontarionightsky.com/sites/cattle-point-star-park.txt): Urban RASC star park in Victoria — accessible, if compromised, city observing.
- [McDonald Park (Abbotsford, BC, Bortle 5)](https://ontarionightsky.com/sites/mcdonald-park.txt): Fraser Valley RASC dark-sky park — closest designated site to Vancouver.
- [Blomidon (Bay of Fundy, NS, Bortle 3)](https://ontarionightsky.com/sites/blomidon-pp.txt): Basalt cliffs over the Minas Basin — dark, elevated, and gale-prone.
- [Gros Morne (Western NL, Bortle 2)](https://ontarionightsky.com/sites/gros-morne-np.txt): UNESCO fjords at 50° north — aurora, low light pollution, dramatic coastal horizons.
- [Cherry Springs (PA Wilds, Bortle 2)](https://ontarionightsky.com/sites/cherry-springs-sp.txt): The East Coast's darkest, with a purpose-built astronomy field and Bortle 2 sky.
- [Big Bend (West TX, Bortle 1)](https://ontarionightsky.com/sites/big-bend-np.txt): Least-light-polluted national park in the lower 48 — desert Bortle 1 skies.
- [Big Bend Ranch (West TX, Bortle 1)](https://ontarionightsky.com/sites/big-bend-ranch-sp.txt): Even darker than the national park — Texas's largest DSP.
- [McDonald Observatory (Davis Mountains, TX, Bortle 2)](https://ontarionightsky.com/sites/mcdonald-observatory.txt): Research observatory with public Star Parties three nights a week.
- [Enchanted Rock (Hill Country, TX, Bortle 3)](https://ontarionightsky.com/sites/enchanted-rock-sna.txt): Pink granite dome DSP — 90 minutes from Austin, elevated 360° horizon.
- [South Llano River (Hill Country, TX, Bortle 2)](https://ontarionightsky.com/sites/south-llano-river-sp.txt): IDA-certified Hill Country park with a walk-in astronomy field.
- [Copper Breaks (Rolling Plains, TX, Bortle 2)](https://ontarionightsky.com/sites/copper-breaks-sp.txt): Texas Panhandle DSP with badland horizons and monthly Star Walks.
- [Death Valley (Mojave, CA/NV, Bortle 1)](https://ontarionightsky.com/sites/death-valley-np.txt): Gold-tier IDA dark-sky park — Bortle 1 basins and 3,000+ visible stars.
- [Joshua Tree (Southern CA, Bortle 3)](https://ontarionightsky.com/sites/joshua-tree-np.txt): High-desert IDA park with iconic silhouettes and Los Angeles light dome to the west.
- [Anza-Borrego (Colorado Desert, CA, Bortle 2)](https://ontarionightsky.com/sites/anza-borrego-sp.txt): California's first IDA-certified state park DSP — 600,000 acres of desert dark.
- [Pinnacles (Central CA, Bortle 3)](https://ontarionightsky.com/sites/pinnacles-np.txt): Volcanic spires and California condors under Bortle 3 coast-range skies.
- [Grand Canyon (Northern AZ, Bortle 2)](https://ontarionightsky.com/sites/grand-canyon-np.txt): IDA-certified — north rim is Bortle 2 with negative-elevation horizon.
- [Petrified Forest (Northern AZ, Bortle 2)](https://ontarionightsky.com/sites/petrified-forest-np.txt): Painted Desert horizons under one of Arizona's darkest skies.
- [Sunset Crater (Flagstaff, AZ, Bortle 3)](https://ontarionightsky.com/sites/sunset-crater-nm.txt): Cinder cone under Flagstaff's IDA-protected dark-sky city.
- [Wupatki (Northern AZ, Bortle 3)](https://ontarionightsky.com/sites/wupatki-nm.txt): Ancestral Puebloan pueblos with wide desert horizons and Flagstaff dark-sky protection.
- [Oracle SP (Santa Catalinas, AZ, Bortle 3)](https://ontarionightsky.com/sites/oracle-sp.txt): IDA-certified Sonoran desert park north of Tucson.
- [Kartchner Caverns (Southern AZ, Bortle 3)](https://ontarionightsky.com/sites/kartchner-caverns-sp.txt): IDA-designated with a dedicated star-party pad.
- [Parashant (NW AZ, Bortle 1)](https://ontarionightsky.com/sites/grand-canyon-parashant-nm.txt): Remote Bortle 1 monument on the Arizona Strip — no services, spectacular sky.
- [Kaibab NF (Northern AZ, Bortle 2)](https://ontarionightsky.com/sites/kaibab-nf.txt): IDA-certified national forest bordering Grand Canyon's North Rim.
- [Canyonlands (Southern UT, Bortle 2)](https://ontarionightsky.com/sites/canyonlands-np.txt): Gold-tier IDA park — Island in the Sky mesa has 360° dark horizon.
- [Arches (Southern UT, Bortle 2)](https://ontarionightsky.com/sites/arches-np.txt): IDA-certified — sandstone arches frame the Milky Way from May to September.
- [Capitol Reef (South-central UT, Bortle 2)](https://ontarionightsky.com/sites/capitol-reef-np.txt): IDA-certified with an annual Heritage Starfest — Waterpocket Fold horizons.
- [Bryce Canyon (Southern UT, Bortle 2)](https://ontarionightsky.com/sites/bryce-canyon-np.txt): 8,000 ft elevation IDA park — thin air, Bortle 2, ranger astronomy programs.
- [Zion (SW UT, Bortle 3)](https://ontarionightsky.com/sites/zion-np.txt): IDA-certified — canyon walls limit horizon but sky quality is excellent.
- [Natural Bridges (SE UT, Bortle 2)](https://ontarionightsky.com/sites/natural-bridges-nm.txt): First IDA-certified International Dark Sky Park in the world (2007).
- [Hovenweep (UT/CO, Bortle 2)](https://ontarionightsky.com/sites/hovenweep-nm.txt): Ancestral Puebloan towers under one of the darkest skies in the lower 48.
- [Cedar Breaks (SW UT, Bortle 2)](https://ontarionightsky.com/sites/cedar-breaks-nm.txt): 10,000 ft IDA park — coldest, driest skies in southern Utah.
- [Antelope Island (Great Salt Lake, UT, Bortle 4)](https://ontarionightsky.com/sites/antelope-island-sp.txt): IDA-certified island in the Great Salt Lake — Salt Lake City dome to the east.
- [North Fork Park (Northern UT, Bortle 3)](https://ontarionightsky.com/sites/weber-county-north-fork-park.txt): IDA-certified Wasatch foothills park — closest true DSP to Ogden and SLC.
- [Rainbow Bridge (SE UT, Bortle 1)](https://ontarionightsky.com/sites/rainbow-bridge-nm.txt): Boat-in-only IDA monument on Lake Powell — Bortle 1 canyon skies.
- [Dinosaur NM (UT/CO, Bortle 2)](https://ontarionightsky.com/sites/dinosaur-nm.txt): IDA-certified — Green and Yampa river canyons at Bortle 2.
- [Chaco Culture (NW NM, Bortle 2)](https://ontarionightsky.com/sites/chaco-nhp.txt): Ancestral Puebloan great houses aligned to solstices — IDA gold-tier.
- [Cosmic Campground (SW NM, Bortle 1)](https://ontarionightsky.com/sites/cosmic-campground.txt): First IDA International Dark Sky Sanctuary in North America — Bortle 1.
- [White Sands (Tularosa Basin, NM, Bortle 3)](https://ontarionightsky.com/sites/white-sands-np.txt): Gypsum dunes reflect starlight — special full-moon and new-moon programs.
- [Salinas Missions (Central NM, Bortle 3)](https://ontarionightsky.com/sites/salinas-pueblo-missions-nm.txt): IDA-certified — mission ruins under central New Mexico dark sky.
- [Mesa Verde (SW CO, Bortle 2)](https://ontarionightsky.com/sites/mesa-verde-np.txt): IDA-certified — cliff-dwelling park at 8,000 ft with Bortle 2 skies.
- [Black Canyon (Western CO, Bortle 2)](https://ontarionightsky.com/sites/black-canyon-gunnison-np.txt): IDA-certified — 2,000 ft-deep canyon rim, some of Colorado's darkest sky.
- [Great Sand Dunes (San Luis Valley, CO, Bortle 2)](https://ontarionightsky.com/sites/great-sand-dunes-np.txt): IDA-certified — tallest dunes in North America under Bortle 2 sky.
- [Curecanti (Western CO, Bortle 2)](https://ontarionightsky.com/sites/curecanti-nra.txt): IDA-certified reservoir DSP adjacent to Black Canyon.
- [Rocky Mountain NP (Northern CO, Bortle 3)](https://ontarionightsky.com/sites/rocky-mountain-np.txt): IDA-certified — high alpine skies with Denver dome to the east.
- [Jackson Lake SP (Northeastern CO, Bortle 3)](https://ontarionightsky.com/sites/dinosaur-ridge-co.txt): IDA-certified reservoir DSP on the eastern plains.
- [Great Basin (Eastern NV, Bortle 2)](https://ontarionightsky.com/sites/great-basin-np.txt): IDA-certified — 13,000 ft peaks, ancient bristlecones, world-class dark.
- [Massacre Rim (NW NV, Bortle 1)](https://ontarionightsky.com/sites/massacre-rim-dss.txt): IDA sanctuary — the largest contiguous dark area in the lower 48.
- [Central Idaho (Sawtooths, ID, Bortle 2)](https://ontarionightsky.com/sites/central-idaho-dsr.txt): IDA gold-tier Reserve — 1,400 sq mi of Sawtooth wilderness.
- [Craters of the Moon (Central ID, Bortle 2)](https://ontarionightsky.com/sites/craters-of-the-moon-nm.txt): IDA-certified lava-field DSP — dark, otherworldly landscape.
- [Bruneau Dunes (SW ID, Bortle 3)](https://ontarionightsky.com/sites/bruneau-dunes-sp.txt): IDA-certified — tallest single-structure dune in North America, on-site observatory.
- [City of Rocks (Southern ID, Bortle 2)](https://ontarionightsky.com/sites/city-of-rocks-nr.txt): IDA-certified granite spires — cool climate, dark Great Basin sky.
- [Steens Mountain (SE OR, Bortle 1)](https://ontarionightsky.com/sites/steens-mountain.txt): 9,700 ft escarpment — one of the darkest, least-visited places in the lower 48.
- [Oregon Outback (SE OR, Bortle 1)](https://ontarionightsky.com/sites/oregon-outback-dss.txt): The world's largest Dark Sky Sanctuary — over 2.5 million acres of Bortle 1.
- [Prineville Reservoir (Central OR, Bortle 2)](https://ontarionightsky.com/sites/prineville-reservoir-sp.txt): First IDA-certified state park in Oregon — high-desert reservoir DSP.
- [Cottonwood Canyon (North-central OR, Bortle 3)](https://ontarionightsky.com/sites/cottonwood-canyon-sp.txt): John Day River canyon DSP — Oregon's second-largest state park.
- [Olympic NP (NW WA, Bortle 3)](https://ontarionightsky.com/sites/olympic-np.txt): Coast, rainforest and alpine — Hurricane Ridge and coastal beaches are darkest.
- [North Cascades (Northern WA, Bortle 2)](https://ontarionightsky.com/sites/north-cascades-np.txt): American Alps — glaciated peaks under Bortle 2 sky.
- [Goldendale Observatory (South-central WA, Bortle 3)](https://ontarionightsky.com/sites/goldendale-observatory-sp.txt): IDA-certified public observatory with a 24.5-inch reflector.
- [Crater Lake (SW OR, Bortle 2)](https://ontarionightsky.com/sites/crater-lake-np.txt): 6,000 ft caldera rim — cold, clear, world-class dark.
- [Denali (Interior AK, Bortle 1)](https://ontarionightsky.com/sites/denali-np.txt): 6-million-acre wilderness at 63° north — aurora September through April.
- [Gates of the Arctic (Northern AK, Bortle 1)](https://ontarionightsky.com/sites/gates-of-the-arctic-np.txt): Above the Arctic Circle — polar night and continuous aurora in winter.
- [Wrangell-St. Elias (SE AK, Bortle 1)](https://ontarionightsky.com/sites/wrangell-st-elias-np.txt): Largest US national park — Bortle 1 across an area the size of Switzerland.
- [Glacier NP (Northern MT, Bortle 2)](https://ontarionightsky.com/sites/glacier-np.txt): US half of Waterton-Glacier International Dark Sky Park.
- [Yellowstone (WY/MT/ID, Bortle 2)](https://ontarionightsky.com/sites/yellowstone-np.txt): Geothermal wilderness at 7,500 ft — dark skies over Grand Prismatic and beyond.
- [Grand Teton (NW WY, Bortle 2)](https://ontarionightsky.com/sites/grand-teton-np.txt): Teton silhouettes over Snake River — Bortle 2 valley skies.
- [Badlands (SW SD, Bortle 2)](https://ontarionightsky.com/sites/badlands-np.txt): Eroded pinnacles under one of the darkest skies east of the Rockies.
- [Theodore Roosevelt (Western ND, Bortle 2)](https://ontarionightsky.com/sites/theodore-roosevelt-np.txt): IDA-certified badlands park — bison, aurora, no city domes.
- [Buffalo National River (Northern AR, Bortle 2)](https://ontarionightsky.com/sites/buffalo-national-river.txt): IDA-certified — Ozark river corridor with cliff-top observing.
- [Voyageurs (Northern MN, Bortle 2)](https://ontarionightsky.com/sites/voyageurs-np.txt): IDA gold-tier — lake wilderness on the Canadian border, aurora regular.
- [Boundary Waters (Northern MN, Bortle 1)](https://ontarionightsky.com/sites/boundary-waters.txt): IDA sanctuary jointly with Quetico — Bortle 1 canoe wilderness.
- [Isle Royale (Lake Superior, MI, Bortle 2)](https://ontarionightsky.com/sites/isle-royale-np.txt): IDA-certified island wilderness — ferry-in, no roads, extraordinary dark.
- [Headlands (Northern MI, Bortle 3)](https://ontarionightsky.com/sites/headlands-dsp.txt): IDA-certified Lake Michigan shore park — free public programs year-round.
- [Dr. T.K. Lawless Park (SW MI, Bortle 3)](https://ontarionightsky.com/sites/dr-tk-lawless-park.txt): IDA-certified county park with hilltop viewing pads.
- [Newport SP (Door County, WI, Bortle 3)](https://ontarionightsky.com/sites/newport-sp-wi.txt): IDA-certified — Wisconsin's only DSP, Lake Michigan shoreline.
- [Shenandoah (Northern VA, Bortle 4)](https://ontarionightsky.com/sites/shenandoah-np.txt): Big Meadows and Skyline Drive overlooks — dark for the mid-Atlantic.
- [Staunton River (Southern VA, Bortle 3)](https://ontarionightsky.com/sites/staunton-river-sp.txt): IDA-certified — hosts the annual Staunton River Star Party.
- [Rappahannock County Park (Northern VA, Bortle 4)](https://ontarionightsky.com/sites/rappahannock-county-park.txt): IDA-certified — Blue Ridge foothill park with a dedicated observing field.
- [Mayland Earth to Sky (Western NC, Bortle 3)](https://ontarionightsky.com/sites/mayland-earth-sky.txt): IDA-certified with a 34-inch research telescope open to the public.
- [PARI (Western NC, Bortle 3)](https://ontarionightsky.com/sites/pisgah-astronomical-research-institute.txt): Former NASA tracking station — public star parties and radio-astronomy tours.
- [Cape Lookout (Outer Banks, NC, Bortle 3)](https://ontarionightsky.com/sites/cape-lookout-ns.txt): IDA-certified barrier-island seashore — Atlantic horizon, no light domes.
- [Stephen Foster SP (Okefenokee, GA, Bortle 2)](https://ontarionightsky.com/sites/stephen-foster-sp.txt): First IDA-certified DSP in the eastern US — Okefenokee swamp horizons.
- [Kissimmee Prairie (Central FL, Bortle 3)](https://ontarionightsky.com/sites/kissimmee-prairie-sp.txt): IDA-certified — Florida's darkest and one of the flattest horizons in the state.
- [Big Cypress (Southern FL, Bortle 3)](https://ontarionightsky.com/sites/big-cypress-npr.txt): IDA-certified — swamp preserve adjacent to Everglades.
- [Everglades (Southern FL, Bortle 4)](https://ontarionightsky.com/sites/everglades-np.txt): River-of-grass horizons — Miami dome to the east, dark to the south and west.
- [Middle Fork (East-central IL, Bortle 4)](https://ontarionightsky.com/sites/middle-fork-forest-preserve.txt): IDA-certified — Illinois's only DSP and the darkest spot in the state.
- [Geauga Observatory Park (NE OH, Bortle 4)](https://ontarionightsky.com/sites/geauga-observatory-park.txt): IDA-certified public observatory east of Cleveland.
- [Katahdin Woods (Northern ME, Bortle 2)](https://ontarionightsky.com/sites/katahdin-woods-waters-nm.txt): IDA sanctuary — Maine's darkest, aurora when Kp ≥ 4.
- [Acadia (Coastal ME, Bortle 4)](https://ontarionightsky.com/sites/acadia-np.txt): Cadillac Mountain and Sand Beach — coastal Bortle 4 sky, dark for the east.

## Per-site structured data

- [Torrance Barrens JSON](https://ontarionightsky.com/sites/torrance-barrens.json)
- [Killarney JSON](https://ontarionightsky.com/sites/killarney.json)
- [Lake Superior JSON](https://ontarionightsky.com/sites/lake-superior.json)
- [Algonquin JSON](https://ontarionightsky.com/sites/algonquin.json)
- [North Frontenac JSON](https://ontarionightsky.com/sites/north-frontenac.json)
- [Bruce Peninsula JSON](https://ontarionightsky.com/sites/bruce-peninsula.json)
- [Point Pelee JSON](https://ontarionightsky.com/sites/point-pelee.json)
- [Manitoulin (Gordon's Park) JSON](https://ontarionightsky.com/sites/manitoulin.json)
- [Quetico JSON](https://ontarionightsky.com/sites/quetico.json)
- [Pukaskwa JSON](https://ontarionightsky.com/sites/pukaskwa.json)
- [Binbrook JSON](https://ontarionightsky.com/sites/binbrook.json)
- [Long Sault JSON](https://ontarionightsky.com/sites/long-sault.json)
- [Jasper NP JSON](https://ontarionightsky.com/sites/jasper-np.json)
- [Wood Buffalo JSON](https://ontarionightsky.com/sites/wood-buffalo-np.json)
- [Mont-Mégantic JSON](https://ontarionightsky.com/sites/mont-megantic.json)
- [Grasslands NP JSON](https://ontarionightsky.com/sites/grasslands-np.json)
- [Cypress Hills JSON](https://ontarionightsky.com/sites/cypress-hills.json)
- [Kejimkujik JSON](https://ontarionightsky.com/sites/kejimkujik-np.json)
- [Kouchibouguac JSON](https://ontarionightsky.com/sites/kouchibouguac-np.json)
- [Fundy NP JSON](https://ontarionightsky.com/sites/fundy-np.json)
- [Terra Nova JSON](https://ontarionightsky.com/sites/terra-nova-np.json)
- [Elk Island JSON](https://ontarionightsky.com/sites/elk-island-np.json)
- [Riding Mountain JSON](https://ontarionightsky.com/sites/riding-mountain-np.json)
- [Prince Albert NP JSON](https://ontarionightsky.com/sites/prince-albert-np.json)
- [Waterton Lakes JSON](https://ontarionightsky.com/sites/waterton-lakes-np.json)
- [La Mauricie JSON](https://ontarionightsky.com/sites/la-mauricie-np.json)
- [Kluane JSON](https://ontarionightsky.com/sites/kluane-np.json)
- [Nahanni JSON](https://ontarionightsky.com/sites/nahanni-npr.json)
- [Bon Echo JSON](https://ontarionightsky.com/sites/bon-echo-pp.json)
- [Pinery JSON](https://ontarionightsky.com/sites/pinery-pp.json)
- [Cattle Point JSON](https://ontarionightsky.com/sites/cattle-point-star-park.json)
- [McDonald Park JSON](https://ontarionightsky.com/sites/mcdonald-park.json)
- [Blomidon JSON](https://ontarionightsky.com/sites/blomidon-pp.json)
- [Gros Morne JSON](https://ontarionightsky.com/sites/gros-morne-np.json)
- [Cherry Springs JSON](https://ontarionightsky.com/sites/cherry-springs-sp.json)
- [Big Bend JSON](https://ontarionightsky.com/sites/big-bend-np.json)
- [Big Bend Ranch JSON](https://ontarionightsky.com/sites/big-bend-ranch-sp.json)
- [McDonald Observatory JSON](https://ontarionightsky.com/sites/mcdonald-observatory.json)
- [Enchanted Rock JSON](https://ontarionightsky.com/sites/enchanted-rock-sna.json)
- [South Llano River JSON](https://ontarionightsky.com/sites/south-llano-river-sp.json)
- [Copper Breaks JSON](https://ontarionightsky.com/sites/copper-breaks-sp.json)
- [Death Valley JSON](https://ontarionightsky.com/sites/death-valley-np.json)
- [Joshua Tree JSON](https://ontarionightsky.com/sites/joshua-tree-np.json)
- [Anza-Borrego JSON](https://ontarionightsky.com/sites/anza-borrego-sp.json)
- [Pinnacles JSON](https://ontarionightsky.com/sites/pinnacles-np.json)
- [Grand Canyon JSON](https://ontarionightsky.com/sites/grand-canyon-np.json)
- [Petrified Forest JSON](https://ontarionightsky.com/sites/petrified-forest-np.json)
- [Sunset Crater JSON](https://ontarionightsky.com/sites/sunset-crater-nm.json)
- [Wupatki JSON](https://ontarionightsky.com/sites/wupatki-nm.json)
- [Oracle SP JSON](https://ontarionightsky.com/sites/oracle-sp.json)
- [Kartchner Caverns JSON](https://ontarionightsky.com/sites/kartchner-caverns-sp.json)
- [Parashant JSON](https://ontarionightsky.com/sites/grand-canyon-parashant-nm.json)
- [Kaibab NF JSON](https://ontarionightsky.com/sites/kaibab-nf.json)
- [Canyonlands JSON](https://ontarionightsky.com/sites/canyonlands-np.json)
- [Arches JSON](https://ontarionightsky.com/sites/arches-np.json)
- [Capitol Reef JSON](https://ontarionightsky.com/sites/capitol-reef-np.json)
- [Bryce Canyon JSON](https://ontarionightsky.com/sites/bryce-canyon-np.json)
- [Zion JSON](https://ontarionightsky.com/sites/zion-np.json)
- [Natural Bridges JSON](https://ontarionightsky.com/sites/natural-bridges-nm.json)
- [Hovenweep JSON](https://ontarionightsky.com/sites/hovenweep-nm.json)
- [Cedar Breaks JSON](https://ontarionightsky.com/sites/cedar-breaks-nm.json)
- [Antelope Island JSON](https://ontarionightsky.com/sites/antelope-island-sp.json)
- [North Fork Park JSON](https://ontarionightsky.com/sites/weber-county-north-fork-park.json)
- [Rainbow Bridge JSON](https://ontarionightsky.com/sites/rainbow-bridge-nm.json)
- [Dinosaur NM JSON](https://ontarionightsky.com/sites/dinosaur-nm.json)
- [Chaco Culture JSON](https://ontarionightsky.com/sites/chaco-nhp.json)
- [Cosmic Campground JSON](https://ontarionightsky.com/sites/cosmic-campground.json)
- [White Sands JSON](https://ontarionightsky.com/sites/white-sands-np.json)
- [Salinas Missions JSON](https://ontarionightsky.com/sites/salinas-pueblo-missions-nm.json)
- [Mesa Verde JSON](https://ontarionightsky.com/sites/mesa-verde-np.json)
- [Black Canyon JSON](https://ontarionightsky.com/sites/black-canyon-gunnison-np.json)
- [Great Sand Dunes JSON](https://ontarionightsky.com/sites/great-sand-dunes-np.json)
- [Curecanti JSON](https://ontarionightsky.com/sites/curecanti-nra.json)
- [Rocky Mountain NP JSON](https://ontarionightsky.com/sites/rocky-mountain-np.json)
- [Jackson Lake SP JSON](https://ontarionightsky.com/sites/dinosaur-ridge-co.json)
- [Great Basin JSON](https://ontarionightsky.com/sites/great-basin-np.json)
- [Massacre Rim JSON](https://ontarionightsky.com/sites/massacre-rim-dss.json)
- [Central Idaho JSON](https://ontarionightsky.com/sites/central-idaho-dsr.json)
- [Craters of the Moon JSON](https://ontarionightsky.com/sites/craters-of-the-moon-nm.json)
- [Bruneau Dunes JSON](https://ontarionightsky.com/sites/bruneau-dunes-sp.json)
- [City of Rocks JSON](https://ontarionightsky.com/sites/city-of-rocks-nr.json)
- [Steens Mountain JSON](https://ontarionightsky.com/sites/steens-mountain.json)
- [Oregon Outback JSON](https://ontarionightsky.com/sites/oregon-outback-dss.json)
- [Prineville Reservoir JSON](https://ontarionightsky.com/sites/prineville-reservoir-sp.json)
- [Cottonwood Canyon JSON](https://ontarionightsky.com/sites/cottonwood-canyon-sp.json)
- [Olympic NP JSON](https://ontarionightsky.com/sites/olympic-np.json)
- [North Cascades JSON](https://ontarionightsky.com/sites/north-cascades-np.json)
- [Goldendale Observatory JSON](https://ontarionightsky.com/sites/goldendale-observatory-sp.json)
- [Crater Lake JSON](https://ontarionightsky.com/sites/crater-lake-np.json)
- [Denali JSON](https://ontarionightsky.com/sites/denali-np.json)
- [Gates of the Arctic JSON](https://ontarionightsky.com/sites/gates-of-the-arctic-np.json)
- [Wrangell-St. Elias JSON](https://ontarionightsky.com/sites/wrangell-st-elias-np.json)
- [Glacier NP JSON](https://ontarionightsky.com/sites/glacier-np.json)
- [Yellowstone JSON](https://ontarionightsky.com/sites/yellowstone-np.json)
- [Grand Teton JSON](https://ontarionightsky.com/sites/grand-teton-np.json)
- [Badlands JSON](https://ontarionightsky.com/sites/badlands-np.json)
- [Theodore Roosevelt JSON](https://ontarionightsky.com/sites/theodore-roosevelt-np.json)
- [Buffalo National River JSON](https://ontarionightsky.com/sites/buffalo-national-river.json)
- [Voyageurs JSON](https://ontarionightsky.com/sites/voyageurs-np.json)
- [Boundary Waters JSON](https://ontarionightsky.com/sites/boundary-waters.json)
- [Isle Royale JSON](https://ontarionightsky.com/sites/isle-royale-np.json)
- [Headlands JSON](https://ontarionightsky.com/sites/headlands-dsp.json)
- [Dr. T.K. Lawless Park JSON](https://ontarionightsky.com/sites/dr-tk-lawless-park.json)
- [Newport SP JSON](https://ontarionightsky.com/sites/newport-sp-wi.json)
- [Shenandoah JSON](https://ontarionightsky.com/sites/shenandoah-np.json)
- [Staunton River JSON](https://ontarionightsky.com/sites/staunton-river-sp.json)
- [Rappahannock County Park JSON](https://ontarionightsky.com/sites/rappahannock-county-park.json)
- [Mayland Earth to Sky JSON](https://ontarionightsky.com/sites/mayland-earth-sky.json)
- [PARI JSON](https://ontarionightsky.com/sites/pisgah-astronomical-research-institute.json)
- [Cape Lookout JSON](https://ontarionightsky.com/sites/cape-lookout-ns.json)
- [Stephen Foster SP JSON](https://ontarionightsky.com/sites/stephen-foster-sp.json)
- [Kissimmee Prairie JSON](https://ontarionightsky.com/sites/kissimmee-prairie-sp.json)
- [Big Cypress JSON](https://ontarionightsky.com/sites/big-cypress-npr.json)
- [Everglades JSON](https://ontarionightsky.com/sites/everglades-np.json)
- [Middle Fork JSON](https://ontarionightsky.com/sites/middle-fork-forest-preserve.json)
- [Geauga Observatory Park JSON](https://ontarionightsky.com/sites/geauga-observatory-park.json)
- [Katahdin Woods JSON](https://ontarionightsky.com/sites/katahdin-woods-waters-nm.json)
- [Acadia JSON](https://ontarionightsky.com/sites/acadia-np.json)

## How the score works

The tonight score blends seven hourly metrics — cloud cover, transparency, seeing, astronomical darkness (sun + moon), smoke (US-AQI / PM2.5), humidity and temperature — weighted by the user's observing mode (visual, deep-sky, planetary or astrophoto), then adds a Bortle-aware darkness bonus so darker sites score higher for deep-sky targets.

## Optional

- [Sitemap](https://ontarionightsky.com/sitemap.xml)
- [robots.txt](https://ontarionightsky.com/robots.txt)
- [Web app manifest](https://ontarionightsky.com/site.webmanifest)