{"assessment":{"best_window":null,"cost":{"altitude":0.0,"clouds":7.93,"darkness":2.52,"moon":1.31},"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 10.7 of 10.7 dark hours \u2014 the sky is closed whatever the geometry says.","headline":"Not tonight","hourly":[{"alt":null,"cloud":100,"high":55,"iso":"2026-03-24T17:00Z","label":"unusable","low":100,"mid":40,"moon_alt":66,"precip":0.3,"q":0.0,"rh":96,"sky":"civil twilight","temp":-2.1,"time":"19:00","wind":17.3},{"alt":null,"cloud":100,"high":98,"iso":"2026-03-24T18:00Z","label":"unusable","low":100,"mid":1,"moon_alt":56,"precip":0.3,"q":0.0,"rh":97,"sky":"astronomical twilight","temp":-2.1,"time":"20:00","wind":14.6},{"alt":null,"cloud":100,"high":91,"iso":"2026-03-24T19:00Z","label":"unusable","low":100,"mid":34,"moon_alt":45,"precip":0.2,"q":0.0,"rh":96,"sky":"night","temp":-2.0,"time":"21:00","wind":14.5},{"alt":null,"cloud":100,"high":20,"iso":"2026-03-24T20:00Z","label":"unusable","low":100,"mid":79,"moon_alt":34,"precip":0.5,"q":0.0,"rh":98,"sky":"night","temp":-2.2,"time":"22:00","wind":13.1},{"alt":null,"cloud":100,"high":77,"iso":"2026-03-24T21:00Z","label":"unusable","low":100,"mid":97,"moon_alt":24,"precip":0.8,"q":0.0,"rh":97,"sky":"night","temp":-2.1,"time":"23:00","wind":13.1},{"alt":null,"cloud":100,"high":80,"iso":"2026-03-24T22:00Z","label":"unusable","low":100,"mid":81,"moon_alt":14,"precip":0.6,"q":0.0,"rh":97,"sky":"night","temp":-2.3,"time":"00:00","wind":11.4},{"alt":null,"cloud":100,"high":68,"iso":"2026-03-24T23:00Z","label":"unusable","low":100,"mid":81,"moon_alt":4,"precip":0.6,"q":0.0,"rh":97,"sky":"night","temp":-2.3,"time":"01:00","wind":11.5},{"alt":null,"cloud":100,"high":19,"iso":"2026-03-25T00:00Z","label":"unusable","low":100,"mid":91,"moon_alt":-4,"precip":0.5,"q":0.0,"rh":96,"sky":"night","temp":-2.2,"time":"02:00","wind":12.9},{"alt":null,"cloud":100,"high":67,"iso":"2026-03-25T01:00Z","label":"unusable","low":100,"mid":100,"moon_alt":-11,"precip":0.3,"q":0.0,"rh":96,"sky":"night","temp":-2.1,"time":"03:00","wind":12.2},{"alt":null,"cloud":100,"high":52,"iso":"2026-03-25T02:00Z","label":"unusable","low":100,"mid":5,"moon_alt":-17,"precip":0.1,"q":0.0,"rh":93,"sky":"night","temp":-1.9,"time":"04:00","wind":12.7},{"alt":null,"cloud":95,"high":13,"iso":"2026-03-25T03:00Z","label":"unusable","low":95,"mid":0,"moon_alt":-20,"precip":0.0,"q":0.0,"rh":90,"sky":"astronomical twilight","temp":-1.7,"time":"05:00","wind":13.5},{"alt":null,"cloud":97,"high":41,"iso":"2026-03-25T04:00Z","label":"unusable","low":95,"mid":2,"moon_alt":-21,"precip":0.0,"q":0.0,"rh":89,"sky":"civil twilight","temp":-2.0,"time":"06:00","wind":13.7}],"peak_quality":0.0,"peak_sky":1.0,"quality_hours":0.0,"reasons":["cloud cover cost 7.9 quality-hours","daylight and twilight cost 2.5 quality-hours","moonlight cost 1.3 quality-hours"],"reference_hours":4.0,"score":0,"score_astronomy":100,"score_weather":0,"sky_hours":7.93,"verdict":"unusable","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2026-03-25T04:20Z","end_local":"06:20","hours":11.75,"label":"unusable","mean_quality":0.0,"start":"2026-03-24T16:35Z","start_local":"18:35"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":100,"dark":false,"high":76,"local":"18:00","low":100,"mid":79,"precip":0.6,"rh":96,"temp":-1.9,"time":"2026-03-24T16:00Z","wind":17.3},{"cloud":100,"dark":false,"high":55,"local":"19:00","low":100,"mid":40,"precip":0.3,"rh":96,"temp":-2.1,"time":"2026-03-24T17:00Z","wind":17.3},{"cloud":100,"dark":false,"high":98,"local":"20:00","low":100,"mid":1,"precip":0.3,"rh":97,"temp":-2.1,"time":"2026-03-24T18:00Z","wind":14.6},{"cloud":100,"dark":true,"high":91,"local":"21:00","low":100,"mid":34,"precip":0.2,"rh":96,"temp":-2.0,"time":"2026-03-24T19:00Z","wind":14.5},{"cloud":100,"dark":true,"high":20,"local":"22:00","low":100,"mid":79,"precip":0.5,"rh":98,"temp":-2.2,"time":"2026-03-24T20:00Z","wind":13.1},{"cloud":100,"dark":true,"high":77,"local":"23:00","low":100,"mid":97,"precip":0.8,"rh":97,"temp":-2.1,"time":"2026-03-24T21:00Z","wind":13.1},{"cloud":100,"dark":true,"high":80,"local":"00:00","low":100,"mid":81,"precip":0.6,"rh":97,"temp":-2.3,"time":"2026-03-24T22:00Z","wind":11.4},{"cloud":100,"dark":true,"high":68,"local":"01:00","low":100,"mid":81,"precip":0.6,"rh":97,"temp":-2.3,"time":"2026-03-24T23:00Z","wind":11.5},{"cloud":100,"dark":true,"high":19,"local":"02:00","low":100,"mid":91,"precip":0.5,"rh":96,"temp":-2.2,"time":"2026-03-25T00:00Z","wind":12.9},{"cloud":100,"dark":true,"high":67,"local":"03:00","low":100,"mid":100,"precip":0.3,"rh":96,"temp":-2.1,"time":"2026-03-25T01:00Z","wind":12.2},{"cloud":100,"dark":true,"high":52,"local":"04:00","low":100,"mid":5,"precip":0.1,"rh":93,"temp":-1.9,"time":"2026-03-25T02:00Z","wind":12.7},{"cloud":95,"dark":false,"high":13,"local":"05:00","low":95,"mid":0,"precip":0.0,"rh":90,"temp":-1.7,"time":"2026-03-25T03:00Z","wind":13.5},{"cloud":97,"dark":false,"high":41,"local":"06:00","low":95,"mid":2,"precip":0.0,"rh":89,"temp":-2.0,"time":"2026-03-25T04:00Z","wind":13.7},{"cloud":99,"dark":false,"high":2,"local":"07:00","low":99,"mid":0,"precip":0.0,"rh":87,"temp":-1.6,"time":"2026-03-25T05:00Z","wind":13.3}],"forecast_source":"history","forecast_updated_at":"2026-10-14T22:38:38Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2026-03-24T18:11:30Z","dark_hours":8.51,"dark_to":"2026-03-25T02:42:17Z","moon":{"illumination":0.401,"phase":"waxing crescent","waxing":true},"moon_free_dark_hours":3.22,"moonrise":"2026-03-25T08:16:04Z","moonset":"2026-03-24T23:28:53Z","sunrise":"2026-03-25T04:16:13Z","sunset":"2026-03-24T16:37:27Z","twilight":{"astronomical":{"end":"2026-03-24T18:11:30Z","start":"2026-03-25T02:42:17Z"},"civil":{"end":"2026-03-24T17:05:17Z","start":"2026-03-25T03:48:26Z"},"nautical":{"end":"2026-03-24T17:37:59Z","start":"2026-03-25T03:15:46Z"}},"window_end":"2026-03-25T10:00:00Z","window_start":"2026-03-24T10:00:00Z"},"night_date":"2026-03-24","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}