Great Sand Dunes stargazing forecast — Friday, August 14

San Luis Valley, CO · Bortle 2 · 37.733, -105.512 · Snapshot generated Sat, 15 Aug 2026 02:05:07 GMT

Poor (Medium confidence)

No sustained clear window; brief gaps possible (min cloud 27%).

Best observing window tonight

Fri 4:00 p.m. – Fri 4:00 p.m. (1h, 27% mean cloud)

Astronomical night: Fri 1:56 p.m. → Sat 12:18 a.m.
Moon: New moon · 2% illuminated
Mean cloud (during night): 82% (min 27%)

Site

Great Sand Dunes protects the tallest sand dunes in North America, rising against the backdrop of the Sangre de Cristo Mountains in a remote corner of the San Luis Valley. Its distance from any large city gives it consistently pristine, quiet skies.

Drive from Toronto: Off Highway 150, about 35 miles north-east of Alamosa, Colorado.

Best time of year: August and September for the clearest, most stable summer-constellation skies, per NPS guidance.

Open the live 48-hour forecast →

Citations & data sources

Open-Meteo Forecast API (cloud, humidity, wind, visibility)
Open-Meteo astronomical data (sunrise, sunset, moon)
Bortle scale reference for site darkness
Editorial guide for Great Sand Dunes: /sites/great-sand-dunes-np.txt
Structured site data: /sites/great-sand-dunes-np.json
Live MCP server (AI agents): https://koohxdehsweadgdegrly.supabase.co/functions/v1/mcp

This is a build-time snapshot — the live forecast at https://ontarionightsky.com/?site=great-sand-dunes-np updates continuously.