{"assessment":{"best_window":{"end":"2025-05-20T21:00Z","end_local":"00:00","hours":1.33,"label":"good","mean_quality":0.92,"start":"2025-05-20T19:40Z","start_local":"22:40"},"cost":{"altitude":0.0,"clouds":3.36,"darkness":3.13,"moon":0.36},"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":"Possible, with compromises","hourly":[{"alt":null,"cloud":30,"high":5,"iso":"2025-05-20T18:00Z","label":"unusable","low":25,"mid":5,"moon_alt":-57,"precip":0.0,"q":0.0,"rh":83,"sky":"civil twilight","temp":6.5,"time":"21:00","wind":1.8},{"alt":null,"cloud":18,"high":0,"iso":"2025-05-20T19:00Z","label":"marginal","low":18,"mid":0,"moon_alt":-50,"precip":0.0,"q":0.4,"rh":85,"sky":"astronomical twilight","temp":5.7,"time":"22:00","wind":1.5},{"alt":null,"cloud":4,"high":3,"iso":"2025-05-20T20:00Z","label":"good","low":1,"mid":0,"moon_alt":-40,"precip":0.0,"q":0.96,"rh":87,"sky":"night","temp":4.8,"time":"23:00","wind":1.8},{"alt":null,"cloud":87,"high":87,"iso":"2025-05-20T21:00Z","label":"unusable","low":0,"mid":0,"moon_alt":-30,"precip":0.0,"q":0.0,"rh":87,"sky":"night","temp":4.0,"time":"00:00","wind":2.3},{"alt":null,"cloud":100,"high":100,"iso":"2025-05-20T22:00Z","label":"unusable","low":0,"mid":0,"moon_alt":-19,"precip":0.0,"q":0.0,"rh":85,"sky":"night","temp":3.5,"time":"01:00","wind":2.8},{"alt":null,"cloud":83,"high":83,"iso":"2025-05-20T23:00Z","label":"unusable","low":0,"mid":0,"moon_alt":-8,"precip":0.0,"q":0.0,"rh":83,"sky":"night","temp":3.4,"time":"02:00","wind":2.7},{"alt":null,"cloud":1,"high":0,"iso":"2025-05-21T00:00Z","label":"good","low":0,"mid":1,"moon_alt":3,"precip":0.0,"q":0.8,"rh":82,"sky":"night","temp":3.2,"time":"03:00","wind":3.4},{"alt":null,"cloud":49,"high":49,"iso":"2025-05-21T01:00Z","label":"poor","low":0,"mid":0,"moon_alt":13,"precip":0.0,"q":0.18,"rh":82,"sky":"astronomical twilight","temp":2.7,"time":"04:00","wind":4.1},{"alt":null,"cloud":2,"high":2,"iso":"2025-05-21T02:00Z","label":"poor","low":0,"mid":0,"moon_alt":22,"precip":0.0,"q":0.11,"rh":82,"sky":"nautical twilight","temp":2.6,"time":"05:00","wind":3.6}],"peak_quality":0.96,"peak_sky":1.0,"quality_hours":2.56,"reasons":["cloud cover cost 3.4 quality-hours","daylight and twilight cost 3.1 quality-hours","moonlight cost 0.4 quality-hours"],"reference_hours":4.0,"score":43,"score_astronomy":100,"score_weather":43,"sky_hours":5.92,"verdict":"marginal","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2025-05-20T18:15Z","end_local":"21:15","hours":0.67,"label":"unusable","mean_quality":0.0,"start":"2025-05-20T17:35Z","start_local":"20:35"},{"end":"2025-05-20T18:55Z","end_local":"21:55","hours":0.67,"label":"poor","mean_quality":0.1,"start":"2025-05-20T18:15Z","start_local":"21:15"},{"end":"2025-05-20T19:40Z","end_local":"22:40","hours":0.75,"label":"marginal","mean_quality":0.39,"start":"2025-05-20T18:55Z","start_local":"21:55"},{"end":"2025-05-20T21:00Z","end_local":"00:00","hours":1.33,"label":"good","mean_quality":0.92,"start":"2025-05-20T19:40Z","start_local":"22:40"},{"end":"2025-05-21T00:00Z","end_local":"03:00","hours":3.0,"label":"unusable","mean_quality":0.0,"start":"2025-05-20T21:00Z","start_local":"00:00"},{"end":"2025-05-21T01:00Z","end_local":"04:00","hours":1.0,"label":"good","mean_quality":0.79,"start":"2025-05-21T00:00Z","start_local":"03:00"},{"end":"2025-05-21T02:25Z","end_local":"05:25","hours":1.42,"label":"poor","mean_quality":0.13,"start":"2025-05-21T01:00Z","start_local":"04:00"},{"end":"2025-05-21T03:00Z","end_local":"06:00","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2025-05-21T02:25Z","start_local":"05:25"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":29,"dark":false,"high":0,"local":"20:00","low":20,"mid":13,"precip":0.0,"rh":81,"temp":8.2,"time":"2025-05-20T17:00Z","wind":2.3},{"cloud":30,"dark":false,"high":5,"local":"21:00","low":25,"mid":5,"precip":0.0,"rh":83,"temp":6.5,"time":"2025-05-20T18:00Z","wind":1.8},{"cloud":18,"dark":false,"high":0,"local":"22:00","low":18,"mid":0,"precip":0.0,"rh":85,"temp":5.7,"time":"2025-05-20T19:00Z","wind":1.5},{"cloud":4,"dark":true,"high":3,"local":"23:00","low":1,"mid":0,"precip":0.0,"rh":87,"temp":4.8,"time":"2025-05-20T20:00Z","wind":1.8},{"cloud":87,"dark":true,"high":87,"local":"00:00","low":0,"mid":0,"precip":0.0,"rh":87,"temp":4.0,"time":"2025-05-20T21:00Z","wind":2.3},{"cloud":100,"dark":true,"high":100,"local":"01:00","low":0,"mid":0,"precip":0.0,"rh":85,"temp":3.5,"time":"2025-05-20T22:00Z","wind":2.8},{"cloud":83,"dark":true,"high":83,"local":"02:00","low":0,"mid":0,"precip":0.0,"rh":83,"temp":3.4,"time":"2025-05-20T23:00Z","wind":2.7},{"cloud":1,"dark":true,"high":0,"local":"03:00","low":0,"mid":1,"precip":0.0,"rh":82,"temp":3.2,"time":"2025-05-21T00:00Z","wind":3.4},{"cloud":49,"dark":false,"high":49,"local":"04:00","low":0,"mid":0,"precip":0.0,"rh":82,"temp":2.7,"time":"2025-05-21T01:00Z","wind":4.1},{"cloud":2,"dark":false,"high":2,"local":"05:00","low":0,"mid":0,"precip":0.0,"rh":82,"temp":2.6,"time":"2025-05-21T02:00Z","wind":3.6},{"cloud":57,"dark":false,"high":57,"local":"06:00","low":0,"mid":0,"precip":0.0,"rh":79,"temp":2.8,"time":"2025-05-21T03:00Z","wind":3.1}],"forecast_source":"history","forecast_updated_at":"2026-10-26T21:34:18Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-05-20T19:38:15Z","dark_hours":5.31,"dark_to":"2025-05-21T00:56:40Z","moon":{"illumination":0.453,"phase":"waning crescent","waxing":false},"moon_free_dark_hours":4.1,"moonrise":"2025-05-20T23:45:10Z","moonset":"2025-05-20T09:34:55Z","sunrise":"2025-05-21T02:55:59Z","sunset":"2025-05-20T17:38:56Z","twilight":{"astronomical":{"end":"2025-05-20T19:38:15Z","start":"2025-05-21T00:56:40Z"},"civil":{"end":"2025-05-20T18:11:17Z","start":"2025-05-21T02:23:38Z"},"nautical":{"end":"2025-05-20T18:51:54Z","start":"2025-05-21T01:43:02Z"}},"window_end":"2025-05-21T09:00:00Z","window_start":"2025-05-20T09:00:00Z"},"night_date":"2025-05-20","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}
