{"assessment":{"best_window":null,"cost":{"altitude":0.0,"clouds":10.85,"darkness":2.58,"moon":0.24},"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 12.6 of 12.6 dark hours \u2014 the sky is closed whatever the geometry says.","headline":"Not tonight","hourly":[{"alt":null,"cloud":100,"high":0,"iso":"2026-02-11T16:00Z","label":"unusable","low":100,"mid":0,"moon_alt":-64,"precip":0.0,"q":0.0,"rh":98,"sky":"civil twilight","temp":-2.4,"time":"18:00","wind":8.4},{"alt":null,"cloud":100,"high":69,"iso":"2026-02-11T17:00Z","label":"unusable","low":100,"mid":0,"moon_alt":-73,"precip":0.0,"q":0.0,"rh":99,"sky":"astronomical twilight","temp":-2.2,"time":"19:00","wind":9.4},{"alt":null,"cloud":100,"high":52,"iso":"2026-02-11T18:00Z","label":"unusable","low":100,"mid":0,"moon_alt":-76,"precip":0.0,"q":0.0,"rh":99,"sky":"night","temp":-1.9,"time":"20:00","wind":9.0},{"alt":null,"cloud":100,"high":57,"iso":"2026-02-11T19:00Z","label":"unusable","low":100,"mid":0,"moon_alt":-72,"precip":0.0,"q":0.0,"rh":99,"sky":"night","temp":-2.0,"time":"21:00","wind":9.3},{"alt":null,"cloud":100,"high":100,"iso":"2026-02-11T20:00Z","label":"unusable","low":100,"mid":0,"moon_alt":-62,"precip":0.0,"q":0.0,"rh":98,"sky":"night","temp":-1.8,"time":"22:00","wind":11.3},{"alt":null,"cloud":100,"high":100,"iso":"2026-02-11T21:00Z","label":"unusable","low":100,"mid":6,"moon_alt":-52,"precip":0.0,"q":0.0,"rh":96,"sky":"night","temp":-1.2,"time":"23:00","wind":11.8},{"alt":null,"cloud":100,"high":100,"iso":"2026-02-11T22:00Z","label":"unusable","low":100,"mid":11,"moon_alt":-41,"precip":0.0,"q":0.0,"rh":95,"sky":"night","temp":-0.9,"time":"00:00","wind":11.6},{"alt":null,"cloud":100,"high":100,"iso":"2026-02-11T23:00Z","label":"unusable","low":100,"mid":22,"moon_alt":-31,"precip":0.0,"q":0.0,"rh":96,"sky":"night","temp":-1.0,"time":"01:00","wind":10.9},{"alt":null,"cloud":100,"high":99,"iso":"2026-02-12T00:00Z","label":"unusable","low":100,"mid":24,"moon_alt":-21,"precip":0.0,"q":0.0,"rh":97,"sky":"night","temp":-1.3,"time":"02:00","wind":7.4},{"alt":null,"cloud":100,"high":10,"iso":"2026-02-12T01:00Z","label":"unusable","low":100,"mid":66,"moon_alt":-11,"precip":0.0,"q":0.0,"rh":97,"sky":"night","temp":-1.1,"time":"03:00","wind":5.2},{"alt":null,"cloud":100,"high":98,"iso":"2026-02-12T02:00Z","label":"unusable","low":100,"mid":93,"moon_alt":-2,"precip":0.2,"q":0.0,"rh":99,"sky":"night","temp":-0.9,"time":"04:00","wind":5.5},{"alt":null,"cloud":100,"high":38,"iso":"2026-02-12T03:00Z","label":"unusable","low":100,"mid":100,"moon_alt":6,"precip":0.5,"q":0.0,"rh":100,"sky":"night","temp":-1.3,"time":"05:00","wind":3.9},{"alt":null,"cloud":100,"high":14,"iso":"2026-02-12T04:00Z","label":"unusable","low":100,"mid":100,"moon_alt":12,"precip":0.7,"q":0.0,"rh":100,"sky":"astronomical twilight","temp":-1.4,"time":"06:00","wind":3.1},{"alt":null,"cloud":100,"high":42,"iso":"2026-02-12T05:00Z","label":"unusable","low":100,"mid":99,"moon_alt":17,"precip":0.1,"q":0.0,"rh":100,"sky":"civil twilight","temp":-1.4,"time":"07:00","wind":4.5}],"peak_quality":0.0,"peak_sky":1.0,"quality_hours":0.0,"reasons":["cloud cover cost 10.9 quality-hours","daylight and twilight cost 2.6 quality-hours"],"reference_hours":4.0,"score":0,"score_astronomy":100,"score_weather":0,"sky_hours":10.85,"verdict":"unusable","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2026-02-12T05:25Z","end_local":"07:25","hours":13.67,"label":"unusable","mean_quality":0.0,"start":"2026-02-11T15:45Z","start_local":"17:45"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":98,"dark":false,"high":0,"local":"17:00","low":98,"mid":0,"precip":0.0,"rh":87,"temp":-1.1,"time":"2026-02-11T15:00Z","wind":10.2},{"cloud":100,"dark":false,"high":0,"local":"18:00","low":100,"mid":0,"precip":0.0,"rh":98,"temp":-2.4,"time":"2026-02-11T16:00Z","wind":8.4},{"cloud":100,"dark":false,"high":69,"local":"19:00","low":100,"mid":0,"precip":0.0,"rh":99,"temp":-2.2,"time":"2026-02-11T17:00Z","wind":9.4},{"cloud":100,"dark":true,"high":52,"local":"20:00","low":100,"mid":0,"precip":0.0,"rh":99,"temp":-1.9,"time":"2026-02-11T18:00Z","wind":9.0},{"cloud":100,"dark":true,"high":57,"local":"21:00","low":100,"mid":0,"precip":0.0,"rh":99,"temp":-2.0,"time":"2026-02-11T19:00Z","wind":9.3},{"cloud":100,"dark":true,"high":100,"local":"22:00","low":100,"mid":0,"precip":0.0,"rh":98,"temp":-1.8,"time":"2026-02-11T20:00Z","wind":11.3},{"cloud":100,"dark":true,"high":100,"local":"23:00","low":100,"mid":6,"precip":0.0,"rh":96,"temp":-1.2,"time":"2026-02-11T21:00Z","wind":11.8},{"cloud":100,"dark":true,"high":100,"local":"00:00","low":100,"mid":11,"precip":0.0,"rh":95,"temp":-0.9,"time":"2026-02-11T22:00Z","wind":11.6},{"cloud":100,"dark":true,"high":100,"local":"01:00","low":100,"mid":22,"precip":0.0,"rh":96,"temp":-1.0,"time":"2026-02-11T23:00Z","wind":10.9},{"cloud":100,"dark":true,"high":99,"local":"02:00","low":100,"mid":24,"precip":0.0,"rh":97,"temp":-1.3,"time":"2026-02-12T00:00Z","wind":7.4},{"cloud":100,"dark":true,"high":10,"local":"03:00","low":100,"mid":66,"precip":0.0,"rh":97,"temp":-1.1,"time":"2026-02-12T01:00Z","wind":5.2},{"cloud":100,"dark":true,"high":98,"local":"04:00","low":100,"mid":93,"precip":0.2,"rh":99,"temp":-0.9,"time":"2026-02-12T02:00Z","wind":5.5},{"cloud":100,"dark":true,"high":38,"local":"05:00","low":100,"mid":100,"precip":0.5,"rh":100,"temp":-1.3,"time":"2026-02-12T03:00Z","wind":3.9},{"cloud":100,"dark":false,"high":14,"local":"06:00","low":100,"mid":100,"precip":0.7,"rh":100,"temp":-1.4,"time":"2026-02-12T04:00Z","wind":3.1},{"cloud":100,"dark":false,"high":42,"local":"07:00","low":100,"mid":99,"precip":0.1,"rh":100,"temp":-1.4,"time":"2026-02-12T05:00Z","wind":4.5},{"cloud":100,"dark":false,"high":88,"local":"08:00","low":100,"mid":98,"precip":0.1,"rh":100,"temp":-1.5,"time":"2026-02-12T06:00Z","wind":3.7}],"forecast_source":"history","forecast_updated_at":"2026-10-16T21:03:43Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2026-02-11T17:22:56Z","dark_hours":10.4,"dark_to":"2026-02-12T03:47:03Z","moon":{"illumination":0.28,"phase":"waning crescent","waxing":false},"moon_free_dark_hours":8.85,"moonrise":"2026-02-12T02:14:47Z","moonset":null,"sunrise":"2026-02-12T05:20:39Z","sunset":"2026-02-11T15:49:06Z","twilight":{"astronomical":{"end":"2026-02-11T17:22:56Z","start":"2026-02-12T03:47:03Z"},"civil":{"end":"2026-02-11T16:17:53Z","start":"2026-02-12T04:51:58Z"},"nautical":{"end":"2026-02-11T16:50:37Z","start":"2026-02-12T04:19:18Z"}},"window_end":"2026-02-12T10:00:00Z","window_start":"2026-02-11T10:00:00Z"},"night_date":"2026-02-11","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}