{"assessment":{"best_window":null,"cost":{"altitude":0.0,"clouds":3.76,"darkness":2.66,"moon":8.01},"formula":"astronomy = 100 * min(1, sky_hours / reference_hours) * peak_sky; overall = astronomy * score_weather / 100 (null when the weather is unknown)","hard_limit":"Overcast (\u226580 % cloud) for 11.1 of 13.7 dark hours \u2014 the sky is closed whatever the geometry says.","headline":"Barely","hourly":[{"alt":null,"cloud":34,"high":0,"iso":"2025-12-03T15:00Z","label":"unusable","low":33,"mid":2,"moon_alt":17,"precip":0.0,"q":0.0,"rh":93,"sky":"civil twilight","temp":-0.7,"time":"17:00","wind":4.2},{"alt":null,"cloud":29,"high":0,"iso":"2025-12-03T16:00Z","label":"poor","low":3,"mid":27,"moon_alt":27,"precip":0.0,"q":0.14,"rh":97,"sky":"astronomical twilight","temp":-2.0,"time":"18:00","wind":3.1},{"alt":null,"cloud":98,"high":0,"iso":"2025-12-03T17:00Z","label":"unusable","low":93,"mid":69,"moon_alt":38,"precip":0.0,"q":0.0,"rh":100,"sky":"night","temp":-2.4,"time":"19:00","wind":3.8},{"alt":null,"cloud":100,"high":1,"iso":"2025-12-03T18:00Z","label":"unusable","low":100,"mid":17,"moon_alt":49,"precip":0.0,"q":0.0,"rh":100,"sky":"night","temp":-1.4,"time":"20:00","wind":4.9},{"alt":null,"cloud":100,"high":1,"iso":"2025-12-03T19:00Z","label":"unusable","low":100,"mid":0,"moon_alt":60,"precip":0.0,"q":0.0,"rh":100,"sky":"night","temp":-1.4,"time":"21:00","wind":4.3},{"alt":null,"cloud":100,"high":1,"iso":"2025-12-03T20:00Z","label":"unusable","low":100,"mid":5,"moon_alt":68,"precip":0.0,"q":0.0,"rh":100,"sky":"night","temp":-1.6,"time":"22:00","wind":4.4},{"alt":null,"cloud":100,"high":1,"iso":"2025-12-03T21:00Z","label":"unusable","low":100,"mid":20,"moon_alt":72,"precip":0.0,"q":0.0,"rh":99,"sky":"night","temp":-1.7,"time":"23:00","wind":3.9},{"alt":null,"cloud":100,"high":1,"iso":"2025-12-03T22:00Z","label":"unusable","low":100,"mid":24,"moon_alt":68,"precip":0.0,"q":0.0,"rh":99,"sky":"night","temp":-1.7,"time":"00:00","wind":4.2},{"alt":null,"cloud":100,"high":29,"iso":"2025-12-03T23:00Z","label":"unusable","low":100,"mid":7,"moon_alt":60,"precip":0.0,"q":0.0,"rh":100,"sky":"night","temp":-1.5,"time":"01:00","wind":3.2},{"alt":null,"cloud":61,"high":33,"iso":"2025-12-04T00:00Z","label":"poor","low":20,"mid":30,"moon_alt":50,"precip":0.0,"q":0.1,"rh":99,"sky":"night","temp":-1.3,"time":"02:00","wind":3.2},{"alt":null,"cloud":97,"high":64,"iso":"2025-12-04T01:00Z","label":"unusable","low":84,"mid":51,"moon_alt":39,"precip":0.0,"q":0.0,"rh":100,"sky":"night","temp":-1.9,"time":"03:00","wind":3.0},{"alt":null,"cloud":100,"high":95,"iso":"2025-12-04T02:00Z","label":"unusable","low":76,"mid":71,"moon_alt":29,"precip":0.0,"q":0.0,"rh":100,"sky":"night","temp":-2.1,"time":"04:00","wind":2.8},{"alt":null,"cloud":98,"high":88,"iso":"2025-12-04T03:00Z","label":"unusable","low":0,"mid":80,"moon_alt":18,"precip":0.0,"q":0.0,"rh":94,"sky":"night","temp":-1.9,"time":"05:00","wind":4.3},{"alt":null,"cloud":99,"high":87,"iso":"2025-12-04T04:00Z","label":"unusable","low":0,"mid":93,"moon_alt":8,"precip":0.0,"q":0.0,"rh":87,"sky":"astronomical twilight","temp":-1.6,"time":"06:00","wind":5.1},{"alt":null,"cloud":99,"high":98,"iso":"2025-12-04T05:00Z","label":"unusable","low":0,"mid":37,"moon_alt":-1,"precip":0.0,"q":0.0,"rh":83,"sky":"nautical twilight","temp":-1.6,"time":"07:00","wind":4.9}],"peak_quality":0.26,"peak_sky":0.54,"quality_hours":0.32,"reasons":["moonlight cost 8.0 quality-hours","cloud cover cost 3.8 quality-hours","daylight and twilight cost 2.7 quality-hours"],"reference_hours":4.0,"score":4,"score_astronomy":54,"score_weather":8,"sky_hours":4.08,"verdict":"poor","verdict_astronomy":"marginal","weather_known":true,"windows":[{"end":"2025-12-03T15:25Z","end_local":"17:25","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2025-12-03T14:50Z","start_local":"16:50"},{"end":"2025-12-03T17:00Z","end_local":"19:00","hours":1.58,"label":"poor","mean_quality":0.13,"start":"2025-12-03T15:25Z","start_local":"17:25"},{"end":"2025-12-04T00:00Z","end_local":"02:00","hours":7.0,"label":"unusable","mean_quality":0.0,"start":"2025-12-03T17:00Z","start_local":"19:00"},{"end":"2025-12-04T01:00Z","end_local":"03:00","hours":1.0,"label":"poor","mean_quality":0.11,"start":"2025-12-04T00:00Z","start_local":"02:00"},{"end":"2025-12-04T05:35Z","end_local":"07:35","hours":4.58,"label":"unusable","mean_quality":0.0,"start":"2025-12-04T01:00Z","start_local":"03:00"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":38,"dark":false,"high":0,"local":"16:00","low":38,"mid":2,"precip":0.0,"rh":83,"temp":2.7,"time":"2025-12-03T14:00Z","wind":4.5},{"cloud":34,"dark":false,"high":0,"local":"17:00","low":33,"mid":2,"precip":0.0,"rh":93,"temp":-0.7,"time":"2025-12-03T15:00Z","wind":4.2},{"cloud":29,"dark":false,"high":0,"local":"18:00","low":3,"mid":27,"precip":0.0,"rh":97,"temp":-2.0,"time":"2025-12-03T16:00Z","wind":3.1},{"cloud":98,"dark":true,"high":0,"local":"19:00","low":93,"mid":69,"precip":0.0,"rh":100,"temp":-2.4,"time":"2025-12-03T17:00Z","wind":3.8},{"cloud":100,"dark":true,"high":1,"local":"20:00","low":100,"mid":17,"precip":0.0,"rh":100,"temp":-1.4,"time":"2025-12-03T18:00Z","wind":4.9},{"cloud":100,"dark":true,"high":1,"local":"21:00","low":100,"mid":0,"precip":0.0,"rh":100,"temp":-1.4,"time":"2025-12-03T19:00Z","wind":4.3},{"cloud":100,"dark":true,"high":1,"local":"22:00","low":100,"mid":5,"precip":0.0,"rh":100,"temp":-1.6,"time":"2025-12-03T20:00Z","wind":4.4},{"cloud":100,"dark":true,"high":1,"local":"23:00","low":100,"mid":20,"precip":0.0,"rh":99,"temp":-1.7,"time":"2025-12-03T21:00Z","wind":3.9},{"cloud":100,"dark":true,"high":1,"local":"00:00","low":100,"mid":24,"precip":0.0,"rh":99,"temp":-1.7,"time":"2025-12-03T22:00Z","wind":4.2},{"cloud":100,"dark":true,"high":29,"local":"01:00","low":100,"mid":7,"precip":0.0,"rh":100,"temp":-1.5,"time":"2025-12-03T23:00Z","wind":3.2},{"cloud":61,"dark":true,"high":33,"local":"02:00","low":20,"mid":30,"precip":0.0,"rh":99,"temp":-1.3,"time":"2025-12-04T00:00Z","wind":3.2},{"cloud":97,"dark":true,"high":64,"local":"03:00","low":84,"mid":51,"precip":0.0,"rh":100,"temp":-1.9,"time":"2025-12-04T01:00Z","wind":3.0},{"cloud":100,"dark":true,"high":95,"local":"04:00","low":76,"mid":71,"precip":0.0,"rh":100,"temp":-2.1,"time":"2025-12-04T02:00Z","wind":2.8},{"cloud":98,"dark":true,"high":88,"local":"05:00","low":0,"mid":80,"precip":0.0,"rh":94,"temp":-1.9,"time":"2025-12-04T03:00Z","wind":4.3},{"cloud":99,"dark":false,"high":87,"local":"06:00","low":0,"mid":93,"precip":0.0,"rh":87,"temp":-1.6,"time":"2025-12-04T04:00Z","wind":5.1},{"cloud":99,"dark":false,"high":98,"local":"07:00","low":0,"mid":37,"precip":0.0,"rh":83,"temp":-1.6,"time":"2025-12-04T05:00Z","wind":4.9},{"cloud":99,"dark":false,"high":99,"local":"08:00","low":0,"mid":5,"precip":0.0,"rh":81,"temp":-1.5,"time":"2025-12-04T06:00Z","wind":4.4}],"forecast_source":"history","forecast_updated_at":"2026-10-19T18:33:14Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-12-03T16:30:10Z","dark_hours":11.37,"dark_to":"2025-12-04T03:52:15Z","moon":{"illumination":0.981,"phase":"full moon","waxing":true},"moon_free_dark_hours":0.0,"moonrise":"2025-12-03T13:20:59Z","moonset":"2025-12-04T04:52:25Z","sunrise":"2025-12-04T05:31:38Z","sunset":"2025-12-03T14:50:55Z","twilight":{"astronomical":{"end":"2025-12-03T16:30:10Z","start":"2025-12-04T03:52:15Z"},"civil":{"end":"2025-12-03T15:21:59Z","start":"2025-12-04T05:00:31Z"},"nautical":{"end":"2025-12-03T15:56:37Z","start":"2025-12-04T04:25:50Z"}},"window_end":"2025-12-04T10:00:00Z","window_start":"2025-12-03T10:00:00Z"},"night_date":"2025-12-03","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}
