{ "$schema": "https://ontarionightsky.com/schemas/near-snapshot.v1.json", "version": "1.0", "generatedAt": "2026-08-15T02:05:10.441Z", "snapshotMeta": { "schemaVersion": "1.0", "tieBreakVersion": "2.0.0", "metricsVersion": "1.2.0", "ladder": [ "verdictRank (desc)", "windowHours (desc)", "windowMeanCloudPct (asc)", "tonightMinCloudPct (asc)", "tonightMeanCloudPct (asc)", "bortle (asc — darker wins)", "distanceKm (asc)" ], "changelog": [ { "version": "1.2.0", "date": "2026-04-26", "type": "metrics", "summary": "Added `tieBreakComparisons[]` to each item: per-step a/b values, equality flag, winner, and `decidedBy` marker for the rule that broke the tie." }, { "version": "2.0.0", "date": "2026-04-26", "type": "tieBreak", "summary": "Replaced verdict+distance-only ranking with 7-level ladder (verdict, window length, window cloud, min/mean cloud, bortle, distance)." }, { "version": "1.1.0", "date": "2026-04-26", "type": "metrics", "summary": "Added per-site `tieBreak` block (windowHours, windowMeanCloudPct, tonightMinCloudPct, tonightMeanCloudPct, bortle) for transparency." }, { "version": "1.0.0", "date": "2026-04-25", "type": "schema", "summary": "Initial near-snapshot.v1 schema with bestTonight + closestSites[]." } ], "docs": "https://ontarionightsky.com/llms.txt" }, "city": { "id": "chicago", "name": "Chicago", "region": "IL Metro", "lat": 41.8781, "lon": -87.6298, "population": 9500000 }, "page": { "url": "https://ontarionightsky.com/near/chicago/", "html": "https://ontarionightsky.com/near/chicago/", "json": "https://ontarionightsky.com/near/chicago/snapshot.json" }, "tieBreakLadder": [ "verdictRank (desc)", "windowHours (desc)", "windowMeanCloudPct (asc)", "tonightMinCloudPct (asc)", "tonightMeanCloudPct (asc)", "bortle (asc — darker wins)", "distanceKm (asc)" ], "bestTonight": { "siteId": "newport-sp-wi", "name": "Newport SP", "distanceKm": 378.5, "bortle": 3, "url": "https://ontarionightsky.com/site/newport-sp-wi/", "forecastUrl": "https://ontarionightsky.com/?site=newport-sp-wi", "tonight": { "date": "2026-08-14T19:56", "nightStartIso": "2026-08-14T19:56", "nightEndIso": "2026-08-15T05:49", "moonPhase": "New moon", "moonIlluminationPct": 2, "verdict": "Excellent", "verdictReason": "9h of clear sky (≤30% cloud) during tonight's astronomical night, mean cloud 4%.", "confidence": "High", "meanCloudPct": 4, "minCloudPct": 0, "bestWindow": { "startIso": "2026-08-14T21:00:00.000Z", "endIso": "2026-08-15T05:00:00.000Z", "hours": 9, "meanCloudPct": 1 } }, "tieBreak": { "verdict": "Excellent", "verdictRank": 5, "windowHours": 9, "windowMeanCloudPct": 1, "tonightMinCloudPct": 0, "tonightMeanCloudPct": 4, "bortle": 3, "distanceKm": 378.5 }, "tieBreakComparisons": [ { "vsSiteId": "dr-tk-lawless-park", "vsName": "Dr. T.K. 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