{"assessment":{"best_window":{"end":"2025-07-13T00:55Z","end_local":"03:55","hours":4.83,"label":"marginal","mean_quality":0.41,"start":"2025-07-12T20:05Z","start_local":"23:05"},"cost":{"altitude":0.0,"clouds":0.41,"darkness":3.2,"moon":2.92},"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":7,"high":0,"iso":"2025-07-12T18:00Z","label":"unusable","low":2,"mid":7,"moon_alt":-15,"precip":0.0,"q":0.0,"rh":66,"sky":"civil twilight","temp":13.7,"time":"21:00","wind":2.5},{"alt":null,"cloud":16,"high":0,"iso":"2025-07-12T19:00Z","label":"poor","low":12,"mid":14,"moon_alt":-4,"precip":0.0,"q":0.12,"rh":65,"sky":"nautical twilight","temp":13.1,"time":"22:00","wind":0.8},{"alt":null,"cloud":13,"high":0,"iso":"2025-07-12T20:00Z","label":"poor","low":10,"mid":12,"moon_alt":5,"precip":0.0,"q":0.25,"rh":65,"sky":"astronomical twilight","temp":12.7,"time":"23:00","wind":0.6},{"alt":null,"cloud":26,"high":0,"iso":"2025-07-12T21:00Z","label":"marginal","low":15,"mid":24,"moon_alt":14,"precip":0.0,"q":0.37,"rh":66,"sky":"night","temp":12.3,"time":"00:00","wind":0.2},{"alt":null,"cloud":23,"high":0,"iso":"2025-07-12T22:00Z","label":"marginal","low":22,"mid":18,"moon_alt":21,"precip":0.0,"q":0.36,"rh":66,"sky":"night","temp":11.9,"time":"01:00","wind":1.4},{"alt":null,"cloud":2,"high":0,"iso":"2025-07-12T23:00Z","label":"marginal","low":2,"mid":0,"moon_alt":26,"precip":0.0,"q":0.44,"rh":65,"sky":"night","temp":12.0,"time":"02:00","wind":1.5},{"alt":null,"cloud":0,"high":0,"iso":"2025-07-13T00:00Z","label":"marginal","low":0,"mid":0,"moon_alt":29,"precip":0.0,"q":0.44,"rh":65,"sky":"night","temp":11.7,"time":"03:00","wind":0.9},{"alt":null,"cloud":0,"high":0,"iso":"2025-07-13T01:00Z","label":"poor","low":0,"mid":0,"moon_alt":28,"precip":0.0,"q":0.22,"rh":65,"sky":"astronomical twilight","temp":10.9,"time":"04:00","wind":0.6},{"alt":null,"cloud":0,"high":0,"iso":"2025-07-13T02:00Z","label":"poor","low":0,"mid":0,"moon_alt":25,"precip":0.0,"q":0.07,"rh":66,"sky":"nautical twilight","temp":10.6,"time":"05:00","wind":0.7}],"peak_quality":0.5,"peak_sky":0.58,"quality_hours":2.55,"reasons":["daylight and twilight cost 3.2 quality-hours","moonlight cost 2.9 quality-hours","cloud cover cost 0.4 quality-hours"],"reference_hours":4.0,"score":37,"score_astronomy":43,"score_weather":86,"sky_hours":2.96,"verdict":"poor","verdict_astronomy":"marginal","weather_known":true,"windows":[{"end":"2025-07-12T18:30Z","end_local":"21:30","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2025-07-12T17:55Z","start_local":"20:55"},{"end":"2025-07-12T19:15Z","end_local":"22:15","hours":0.75,"label":"poor","mean_quality":0.13,"start":"2025-07-12T18:30Z","start_local":"21:30"},{"end":"2025-07-12T19:30Z","end_local":"22:30","hours":0.25,"label":"marginal","mean_quality":0.41,"start":"2025-07-12T19:15Z","start_local":"22:15"},{"end":"2025-07-12T20:05Z","end_local":"23:05","hours":0.58,"label":"poor","mean_quality":0.25,"start":"2025-07-12T19:30Z","start_local":"22:30"},{"end":"2025-07-13T00:55Z","end_local":"03:55","hours":4.83,"label":"marginal","mean_quality":0.41,"start":"2025-07-12T20:05Z","start_local":"23:05"},{"end":"2025-07-13T02:25Z","end_local":"05:25","hours":1.5,"label":"poor","mean_quality":0.15,"start":"2025-07-13T00:55Z","start_local":"03:55"},{"end":"2025-07-13T03:00Z","end_local":"06:00","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2025-07-13T02:25Z","start_local":"05:25"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":31,"dark":false,"high":0,"local":"20:00","low":0,"mid":31,"precip":0.0,"rh":58,"temp":15.8,"time":"2025-07-12T17:00Z","wind":4.6},{"cloud":7,"dark":false,"high":0,"local":"21:00","low":2,"mid":7,"precip":0.0,"rh":66,"temp":13.7,"time":"2025-07-12T18:00Z","wind":2.5},{"cloud":16,"dark":false,"high":0,"local":"22:00","low":12,"mid":14,"precip":0.0,"rh":65,"temp":13.1,"time":"2025-07-12T19:00Z","wind":0.8},{"cloud":13,"dark":false,"high":0,"local":"23:00","low":10,"mid":12,"precip":0.0,"rh":65,"temp":12.7,"time":"2025-07-12T20:00Z","wind":0.6},{"cloud":26,"dark":true,"high":0,"local":"00:00","low":15,"mid":24,"precip":0.0,"rh":66,"temp":12.3,"time":"2025-07-12T21:00Z","wind":0.2},{"cloud":23,"dark":true,"high":0,"local":"01:00","low":22,"mid":18,"precip":0.0,"rh":66,"temp":11.9,"time":"2025-07-12T22:00Z","wind":1.4},{"cloud":2,"dark":true,"high":0,"local":"02:00","low":2,"mid":0,"precip":0.0,"rh":65,"temp":12.0,"time":"2025-07-12T23:00Z","wind":1.5},{"cloud":0,"dark":true,"high":0,"local":"03:00","low":0,"mid":0,"precip":0.0,"rh":65,"temp":11.7,"time":"2025-07-13T00:00Z","wind":0.9},{"cloud":0,"dark":false,"high":0,"local":"04:00","low":0,"mid":0,"precip":0.0,"rh":65,"temp":10.9,"time":"2025-07-13T01:00Z","wind":0.6},{"cloud":0,"dark":false,"high":0,"local":"05:00","low":0,"mid":0,"precip":0.0,"rh":66,"temp":10.6,"time":"2025-07-13T02:00Z","wind":0.7},{"cloud":0,"dark":false,"high":0,"local":"06:00","low":0,"mid":0,"precip":0.0,"rh":65,"temp":10.6,"time":"2025-07-13T03:00Z","wind":0.9}],"forecast_source":"history","forecast_updated_at":"2026-10-24T22:57:12Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-07-12T20:00:24Z","dark_hours":4.88,"dark_to":"2025-07-13T00:53:26Z","moon":{"illumination":0.952,"phase":"waning gibbous","waxing":false},"moon_free_dark_hours":0.0,"moonrise":"2025-07-12T19:27:13Z","moonset":"2025-07-13T05:16:29Z","sunrise":"2025-07-13T02:58:11Z","sunset":"2025-07-12T17:55:41Z","twilight":{"astronomical":{"end":"2025-07-12T20:00:24Z","start":"2025-07-13T00:53:26Z"},"civil":{"end":"2025-07-12T18:28:54Z","start":"2025-07-13T02:24:56Z"},"nautical":{"end":"2025-07-12T19:11:06Z","start":"2025-07-13T01:42:45Z"}},"window_end":"2025-07-13T09:00:00Z","window_start":"2025-07-12T09:00:00Z"},"night_date":"2025-07-12","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}