{"assessment":{"best_window":{"end":"2025-10-11T18:40Z","end_local":"21:40","hours":1.33,"label":"good","mean_quality":0.81,"start":"2025-10-11T17:20Z","start_local":"20:20"},"cost":{"altitude":0.0,"clouds":4.19,"darkness":2.41,"moon":3.93},"formula":"astronomy = 100 * min(1, sky_hours / reference_hours) * peak_sky; overall = astronomy * score_weather / 100 (null when the weather is unknown)","hard_limit":null,"headline":"Barely","hourly":[{"alt":null,"cloud":23,"high":0,"iso":"2025-10-11T16:00Z","label":"unusable","low":23,"mid":0,"moon_alt":-17,"precip":0.0,"q":0.0,"rh":78,"sky":"civil twilight","temp":2.2,"time":"19:00","wind":18.8},{"alt":null,"cloud":14,"high":0,"iso":"2025-10-11T17:00Z","label":"marginal","low":14,"mid":0,"moon_alt":-12,"precip":0.0,"q":0.42,"rh":84,"sky":"astronomical twilight","temp":1.6,"time":"20:00","wind":18.3},{"alt":null,"cloud":20,"high":0,"iso":"2025-10-11T18:00Z","label":"good","low":20,"mid":0,"moon_alt":-5,"precip":0.0,"q":0.78,"rh":83,"sky":"night","temp":1.8,"time":"21:00","wind":18.0},{"alt":null,"cloud":37,"high":0,"iso":"2025-10-11T19:00Z","label":"marginal","low":37,"mid":0,"moon_alt":3,"precip":0.0,"q":0.41,"rh":87,"sky":"night","temp":1.4,"time":"22:00","wind":16.5},{"alt":null,"cloud":61,"high":0,"iso":"2025-10-11T20:00Z","label":"poor","low":61,"mid":0,"moon_alt":13,"precip":0.0,"q":0.21,"rh":89,"sky":"night","temp":1.7,"time":"23:00","wind":15.9},{"alt":null,"cloud":84,"high":0,"iso":"2025-10-11T21:00Z","label":"unusable","low":84,"mid":0,"moon_alt":22,"precip":0.0,"q":0.0,"rh":89,"sky":"night","temp":1.9,"time":"00:00","wind":15.5},{"alt":null,"cloud":91,"high":0,"iso":"2025-10-11T22:00Z","label":"unusable","low":91,"mid":0,"moon_alt":33,"precip":0.0,"q":0.0,"rh":88,"sky":"night","temp":2.3,"time":"01:00","wind":15.9},{"alt":null,"cloud":88,"high":0,"iso":"2025-10-11T23:00Z","label":"unusable","low":88,"mid":0,"moon_alt":44,"precip":0.0,"q":0.0,"rh":88,"sky":"night","temp":2.5,"time":"02:00","wind":16.7},{"alt":null,"cloud":81,"high":0,"iso":"2025-10-12T00:00Z","label":"unusable","low":81,"mid":0,"moon_alt":55,"precip":0.0,"q":0.0,"rh":90,"sky":"night","temp":2.4,"time":"03:00","wind":17.6},{"alt":null,"cloud":75,"high":0,"iso":"2025-10-12T01:00Z","label":"poor","low":75,"mid":0,"moon_alt":65,"precip":0.0,"q":0.08,"rh":91,"sky":"night","temp":2.3,"time":"04:00","wind":16.1},{"alt":null,"cloud":100,"high":0,"iso":"2025-10-12T02:00Z","label":"unusable","low":100,"mid":2,"moon_alt":74,"precip":0.0,"q":0.0,"rh":91,"sky":"night","temp":2.6,"time":"05:00","wind":15.9},{"alt":null,"cloud":100,"high":0,"iso":"2025-10-12T03:00Z","label":"unusable","low":100,"mid":2,"moon_alt":76,"precip":0.0,"q":0.0,"rh":90,"sky":"astronomical twilight","temp":3.1,"time":"06:00","wind":14.5},{"alt":null,"cloud":100,"high":0,"iso":"2025-10-12T04:00Z","label":"unusable","low":100,"mid":5,"moon_alt":70,"precip":0.0,"q":0.0,"rh":91,"sky":"nautical twilight","temp":3.1,"time":"07:00","wind":12.4}],"peak_quality":0.84,"peak_sky":1.0,"quality_hours":2.22,"reasons":["cloud cover cost 4.2 quality-hours","moonlight cost 3.9 quality-hours","daylight and twilight cost 2.4 quality-hours"],"reference_hours":4.0,"score":35,"score_astronomy":100,"score_weather":35,"sky_hours":6.41,"verdict":"poor","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2025-10-11T16:15Z","end_local":"19:15","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2025-10-11T15:45Z","start_local":"18:45"},{"end":"2025-10-11T16:50Z","end_local":"19:50","hours":0.58,"label":"poor","mean_quality":0.11,"start":"2025-10-11T16:15Z","start_local":"19:15"},{"end":"2025-10-11T17:20Z","end_local":"20:20","hours":0.5,"label":"marginal","mean_quality":0.41,"start":"2025-10-11T16:50Z","start_local":"19:50"},{"end":"2025-10-11T18:40Z","end_local":"21:40","hours":1.33,"label":"good","mean_quality":0.81,"start":"2025-10-11T17:20Z","start_local":"20:20"},{"end":"2025-10-11T20:00Z","end_local":"23:00","hours":1.33,"label":"marginal","mean_quality":0.44,"start":"2025-10-11T18:40Z","start_local":"21:40"},{"end":"2025-10-11T21:00Z","end_local":"00:00","hours":1.0,"label":"poor","mean_quality":0.21,"start":"2025-10-11T20:00Z","start_local":"23:00"},{"end":"2025-10-12T01:00Z","end_local":"04:00","hours":4.0,"label":"unusable","mean_quality":0.0,"start":"2025-10-11T21:00Z","start_local":"00:00"},{"end":"2025-10-12T02:00Z","end_local":"05:00","hours":1.0,"label":"poor","mean_quality":0.08,"start":"2025-10-12T01:00Z","start_local":"04:00"},{"end":"2025-10-12T04:30Z","end_local":"07:30","hours":2.5,"label":"unusable","mean_quality":0.0,"start":"2025-10-12T02:00Z","start_local":"05:00"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":35,"dark":false,"high":0,"local":"18:00","low":35,"mid":1,"precip":0.1,"rh":75,"temp":3.5,"time":"2025-10-11T15:00Z","wind":18.8},{"cloud":23,"dark":false,"high":0,"local":"19:00","low":23,"mid":0,"precip":0.0,"rh":78,"temp":2.2,"time":"2025-10-11T16:00Z","wind":18.8},{"cloud":14,"dark":false,"high":0,"local":"20:00","low":14,"mid":0,"precip":0.0,"rh":84,"temp":1.6,"time":"2025-10-11T17:00Z","wind":18.3},{"cloud":20,"dark":true,"high":0,"local":"21:00","low":20,"mid":0,"precip":0.0,"rh":83,"temp":1.8,"time":"2025-10-11T18:00Z","wind":18.0},{"cloud":37,"dark":true,"high":0,"local":"22:00","low":37,"mid":0,"precip":0.0,"rh":87,"temp":1.4,"time":"2025-10-11T19:00Z","wind":16.5},{"cloud":61,"dark":true,"high":0,"local":"23:00","low":61,"mid":0,"precip":0.0,"rh":89,"temp":1.7,"time":"2025-10-11T20:00Z","wind":15.9},{"cloud":84,"dark":true,"high":0,"local":"00:00","low":84,"mid":0,"precip":0.0,"rh":89,"temp":1.9,"time":"2025-10-11T21:00Z","wind":15.5},{"cloud":91,"dark":true,"high":0,"local":"01:00","low":91,"mid":0,"precip":0.0,"rh":88,"temp":2.3,"time":"2025-10-11T22:00Z","wind":15.9},{"cloud":88,"dark":true,"high":0,"local":"02:00","low":88,"mid":0,"precip":0.0,"rh":88,"temp":2.5,"time":"2025-10-11T23:00Z","wind":16.7},{"cloud":81,"dark":true,"high":0,"local":"03:00","low":81,"mid":0,"precip":0.0,"rh":90,"temp":2.4,"time":"2025-10-12T00:00Z","wind":17.6},{"cloud":75,"dark":true,"high":0,"local":"04:00","low":75,"mid":0,"precip":0.0,"rh":91,"temp":2.3,"time":"2025-10-12T01:00Z","wind":16.1},{"cloud":100,"dark":true,"high":0,"local":"05:00","low":100,"mid":2,"precip":0.0,"rh":91,"temp":2.6,"time":"2025-10-12T02:00Z","wind":15.9},{"cloud":100,"dark":false,"high":0,"local":"06:00","low":100,"mid":2,"precip":0.0,"rh":90,"temp":3.1,"time":"2025-10-12T03:00Z","wind":14.5},{"cloud":100,"dark":false,"high":0,"local":"07:00","low":100,"mid":5,"precip":0.0,"rh":91,"temp":3.1,"time":"2025-10-12T04:00Z","wind":12.4},{"cloud":100,"dark":false,"high":0,"local":"08:00","low":100,"mid":2,"precip":0.0,"rh":92,"temp":3.2,"time":"2025-10-12T05:00Z","wind":11.0}],"forecast_source":"history","forecast_updated_at":"2026-10-22T07:01:03Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-10-11T17:18:12Z","dark_hours":9.66,"dark_to":"2025-10-12T02:57:32Z","moon":{"illumination":0.702,"phase":"waning gibbous","waxing":false},"moon_free_dark_hours":1.32,"moonrise":"2025-10-11T18:38:17Z","moonset":"2025-10-11T09:49:30Z","sunrise":"2025-10-12T04:29:53Z","sunset":"2025-10-11T15:46:03Z","twilight":{"astronomical":{"end":"2025-10-11T17:18:12Z","start":"2025-10-12T02:57:32Z"},"civil":{"end":"2025-10-11T16:13:54Z","start":"2025-10-12T04:01:58Z"},"nautical":{"end":"2025-10-11T16:46:02Z","start":"2025-10-12T03:29:46Z"}},"window_end":"2025-10-12T09:00:00Z","window_start":"2025-10-11T09:00:00Z"},"night_date":"2025-10-11","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}