{"assessment":{"best_window":{"end":"2025-10-15T21:00Z","end_local":"00:00","hours":1.0,"label":"good","mean_quality":0.84,"start":"2025-10-15T20:00Z","start_local":"23:00"},"cost":{"altitude":0.0,"clouds":8.49,"darkness":2.46,"moon":0.62},"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 8.8 of 12.0 dark hours \u2014 the sky is closed whatever the geometry says.","headline":"Barely","hourly":[{"alt":null,"cloud":98,"high":0,"iso":"2025-10-15T16:00Z","label":"unusable","low":98,"mid":31,"moon_alt":-24,"precip":0.0,"q":0.0,"rh":98,"sky":"civil twilight","temp":3.1,"time":"19:00","wind":2.8},{"alt":null,"cloud":98,"high":0,"iso":"2025-10-15T17:00Z","label":"unusable","low":98,"mid":95,"moon_alt":-29,"precip":0.1,"q":0.0,"rh":98,"sky":"astronomical twilight","temp":2.7,"time":"20:00","wind":3.1},{"alt":null,"cloud":99,"high":0,"iso":"2025-10-15T18:00Z","label":"unusable","low":99,"mid":39,"moon_alt":-31,"precip":0.0,"q":0.0,"rh":98,"sky":"night","temp":2.5,"time":"21:00","wind":0.7},{"alt":null,"cloud":91,"high":0,"iso":"2025-10-15T19:00Z","label":"unusable","low":91,"mid":0,"moon_alt":-30,"precip":0.0,"q":0.0,"rh":98,"sky":"night","temp":2.2,"time":"22:00","wind":2.1},{"alt":null,"cloud":14,"high":0,"iso":"2025-10-15T20:00Z","label":"good","low":13,"mid":2,"moon_alt":-26,"precip":0.0,"q":0.84,"rh":99,"sky":"night","temp":1.4,"time":"23:00","wind":1.0},{"alt":null,"cloud":98,"high":0,"iso":"2025-10-15T21:00Z","label":"unusable","low":98,"mid":10,"moon_alt":-20,"precip":0.0,"q":0.0,"rh":100,"sky":"night","temp":1.4,"time":"00:00","wind":0.9},{"alt":null,"cloud":91,"high":0,"iso":"2025-10-15T22:00Z","label":"unusable","low":90,"mid":10,"moon_alt":-12,"precip":0.0,"q":0.0,"rh":99,"sky":"night","temp":1.3,"time":"01:00","wind":1.3},{"alt":null,"cloud":86,"high":0,"iso":"2025-10-15T23:00Z","label":"unusable","low":85,"mid":2,"moon_alt":-3,"precip":0.0,"q":0.0,"rh":97,"sky":"night","temp":1.1,"time":"02:00","wind":1.4},{"alt":null,"cloud":100,"high":0,"iso":"2025-10-16T00:00Z","label":"unusable","low":100,"mid":0,"moon_alt":7,"precip":0.0,"q":0.0,"rh":99,"sky":"night","temp":0.6,"time":"03:00","wind":1.1},{"alt":null,"cloud":100,"high":0,"iso":"2025-10-16T01:00Z","label":"unusable","low":100,"mid":0,"moon_alt":18,"precip":0.0,"q":0.0,"rh":97,"sky":"night","temp":0.5,"time":"04:00","wind":0.8},{"alt":null,"cloud":46,"high":0,"iso":"2025-10-16T02:00Z","label":"marginal","low":46,"mid":1,"moon_alt":29,"precip":0.0,"q":0.41,"rh":98,"sky":"night","temp":0.4,"time":"05:00","wind":0.7},{"alt":null,"cloud":44,"high":0,"iso":"2025-10-16T03:00Z","label":"marginal","low":44,"mid":2,"moon_alt":39,"precip":0.0,"q":0.42,"rh":98,"sky":"night","temp":-0.1,"time":"06:00","wind":0.8},{"alt":null,"cloud":27,"high":0,"iso":"2025-10-16T04:00Z","label":"poor","low":27,"mid":0,"moon_alt":49,"precip":0.0,"q":0.08,"rh":96,"sky":"nautical twilight","temp":-0.3,"time":"07:00","wind":1.6}],"peak_quality":0.84,"peak_sky":1.0,"quality_hours":1.43,"reasons":["cloud cover cost 8.5 quality-hours","daylight and twilight cost 2.5 quality-hours","moonlight cost 0.6 quality-hours"],"reference_hours":4.0,"score":14,"score_astronomy":100,"score_weather":14,"sky_hours":9.92,"verdict":"poor","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2025-10-15T20:00Z","end_local":"23:00","hours":4.42,"label":"unusable","mean_quality":0.0,"start":"2025-10-15T15:35Z","start_local":"18:35"},{"end":"2025-10-15T21:00Z","end_local":"00:00","hours":1.0,"label":"good","mean_quality":0.84,"start":"2025-10-15T20:00Z","start_local":"23:00"},{"end":"2025-10-16T02:00Z","end_local":"05:00","hours":5.0,"label":"unusable","mean_quality":0.0,"start":"2025-10-15T21:00Z","start_local":"00:00"},{"end":"2025-10-16T03:05Z","end_local":"06:05","hours":1.08,"label":"marginal","mean_quality":0.41,"start":"2025-10-16T02:00Z","start_local":"05:00"},{"end":"2025-10-16T04:10Z","end_local":"07:10","hours":1.08,"label":"poor","mean_quality":0.13,"start":"2025-10-16T03:05Z","start_local":"06:05"},{"end":"2025-10-16T04:35Z","end_local":"07:35","hours":0.42,"label":"unusable","mean_quality":0.0,"start":"2025-10-16T04:10Z","start_local":"07:10"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":81,"dark":false,"high":0,"local":"18:00","low":77,"mid":21,"precip":0.1,"rh":93,"temp":4.2,"time":"2025-10-15T15:00Z","wind":3.3},{"cloud":98,"dark":false,"high":0,"local":"19:00","low":98,"mid":31,"precip":0.0,"rh":98,"temp":3.1,"time":"2025-10-15T16:00Z","wind":2.8},{"cloud":98,"dark":false,"high":0,"local":"20:00","low":98,"mid":95,"precip":0.1,"rh":98,"temp":2.7,"time":"2025-10-15T17:00Z","wind":3.1},{"cloud":99,"dark":true,"high":0,"local":"21:00","low":99,"mid":39,"precip":0.0,"rh":98,"temp":2.5,"time":"2025-10-15T18:00Z","wind":0.7},{"cloud":91,"dark":true,"high":0,"local":"22:00","low":91,"mid":0,"precip":0.0,"rh":98,"temp":2.2,"time":"2025-10-15T19:00Z","wind":2.1},{"cloud":14,"dark":true,"high":0,"local":"23:00","low":13,"mid":2,"precip":0.0,"rh":99,"temp":1.4,"time":"2025-10-15T20:00Z","wind":1.0},{"cloud":98,"dark":true,"high":0,"local":"00:00","low":98,"mid":10,"precip":0.0,"rh":100,"temp":1.4,"time":"2025-10-15T21:00Z","wind":0.9},{"cloud":91,"dark":true,"high":0,"local":"01:00","low":90,"mid":10,"precip":0.0,"rh":99,"temp":1.3,"time":"2025-10-15T22:00Z","wind":1.3},{"cloud":86,"dark":true,"high":0,"local":"02:00","low":85,"mid":2,"precip":0.0,"rh":97,"temp":1.1,"time":"2025-10-15T23:00Z","wind":1.4},{"cloud":100,"dark":true,"high":0,"local":"03:00","low":100,"mid":0,"precip":0.0,"rh":99,"temp":0.6,"time":"2025-10-16T00:00Z","wind":1.1},{"cloud":100,"dark":true,"high":0,"local":"04:00","low":100,"mid":0,"precip":0.0,"rh":97,"temp":0.5,"time":"2025-10-16T01:00Z","wind":0.8},{"cloud":46,"dark":true,"high":0,"local":"05:00","low":46,"mid":1,"precip":0.0,"rh":98,"temp":0.4,"time":"2025-10-16T02:00Z","wind":0.7},{"cloud":44,"dark":true,"high":0,"local":"06:00","low":44,"mid":2,"precip":0.0,"rh":98,"temp":-0.1,"time":"2025-10-16T03:00Z","wind":0.8},{"cloud":27,"dark":false,"high":0,"local":"07:00","low":27,"mid":0,"precip":0.0,"rh":96,"temp":-0.3,"time":"2025-10-16T04:00Z","wind":1.6},{"cloud":33,"dark":false,"high":0,"local":"08:00","low":33,"mid":0,"precip":0.0,"rh":96,"temp":-0.0,"time":"2025-10-16T05:00Z","wind":2.0}],"forecast_source":"history","forecast_updated_at":"2026-10-22T03:46:19Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-10-15T17:11:59Z","dark_hours":9.83,"dark_to":"2025-10-16T03:01:53Z","moon":{"illumination":0.277,"phase":"waning crescent","waxing":false},"moon_free_dark_hours":6.08,"moonrise":"2025-10-15T23:17:21Z","moonset":"2025-10-15T13:01:03Z","sunrise":"2025-10-16T04:34:23Z","sunset":"2025-10-15T15:39:41Z","twilight":{"astronomical":{"end":"2025-10-15T17:11:59Z","start":"2025-10-16T03:01:53Z"},"civil":{"end":"2025-10-15T16:07:40Z","start":"2025-10-16T04:06:20Z"},"nautical":{"end":"2025-10-15T16:39:51Z","start":"2025-10-16T03:34:04Z"}},"window_end":"2025-10-16T09:00:00Z","window_start":"2025-10-15T09:00:00Z"},"night_date":"2025-10-15","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}