{"assessment":{"best_window":null,"cost":{"altitude":0.0,"clouds":9.96,"darkness":2.55,"moon":1.74},"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 13.2 of 13.2 dark hours \u2014 the sky is closed whatever the geometry says.","headline":"Not tonight","hourly":[{"alt":null,"cloud":100,"high":96,"iso":"2026-01-25T16:00Z","label":"unusable","low":100,"mid":1,"moon_alt":62,"precip":0.0,"q":0.0,"rh":100,"sky":"nautical twilight","temp":-0.1,"time":"18:00","wind":10.4},{"alt":null,"cloud":100,"high":100,"iso":"2026-01-25T17:00Z","label":"unusable","low":100,"mid":0,"moon_alt":58,"precip":0.0,"q":0.0,"rh":99,"sky":"astronomical twilight","temp":0.1,"time":"19:00","wind":12.3},{"alt":null,"cloud":100,"high":100,"iso":"2026-01-25T18:00Z","label":"unusable","low":100,"mid":0,"moon_alt":50,"precip":0.0,"q":0.0,"rh":98,"sky":"night","temp":0.3,"time":"20:00","wind":10.7},{"alt":null,"cloud":100,"high":100,"iso":"2026-01-25T19:00Z","label":"unusable","low":100,"mid":2,"moon_alt":41,"precip":0.0,"q":0.0,"rh":96,"sky":"night","temp":0.8,"time":"21:00","wind":12.6},{"alt":null,"cloud":100,"high":100,"iso":"2026-01-25T20:00Z","label":"unusable","low":100,"mid":5,"moon_alt":30,"precip":0.0,"q":0.0,"rh":95,"sky":"night","temp":2.0,"time":"22:00","wind":17.1},{"alt":null,"cloud":100,"high":77,"iso":"2026-01-25T21:00Z","label":"unusable","low":100,"mid":20,"moon_alt":19,"precip":0.1,"q":0.0,"rh":96,"sky":"night","temp":2.2,"time":"23:00","wind":16.6},{"alt":null,"cloud":100,"high":50,"iso":"2026-01-25T22:00Z","label":"unusable","low":100,"mid":51,"moon_alt":9,"precip":0.2,"q":0.0,"rh":100,"sky":"night","temp":1.9,"time":"00:00","wind":15.3},{"alt":null,"cloud":100,"high":65,"iso":"2026-01-25T23:00Z","label":"unusable","low":100,"mid":27,"moon_alt":-1,"precip":0.2,"q":0.0,"rh":100,"sky":"night","temp":1.8,"time":"01:00","wind":15.8},{"alt":null,"cloud":100,"high":99,"iso":"2026-01-26T00:00Z","label":"unusable","low":100,"mid":64,"moon_alt":-11,"precip":0.2,"q":0.0,"rh":99,"sky":"night","temp":1.6,"time":"02:00","wind":12.1},{"alt":null,"cloud":100,"high":98,"iso":"2026-01-26T01:00Z","label":"unusable","low":100,"mid":50,"moon_alt":-19,"precip":0.6,"q":0.0,"rh":100,"sky":"night","temp":1.7,"time":"03:00","wind":13.6},{"alt":null,"cloud":100,"high":13,"iso":"2026-01-26T02:00Z","label":"unusable","low":100,"mid":30,"moon_alt":-26,"precip":0.3,"q":0.0,"rh":100,"sky":"night","temp":1.8,"time":"04:00","wind":15.7},{"alt":null,"cloud":100,"high":33,"iso":"2026-01-26T03:00Z","label":"unusable","low":100,"mid":54,"moon_alt":-30,"precip":0.4,"q":0.0,"rh":100,"sky":"night","temp":1.6,"time":"05:00","wind":19.3},{"alt":null,"cloud":100,"high":97,"iso":"2026-01-26T04:00Z","label":"unusable","low":100,"mid":95,"moon_alt":-32,"precip":0.9,"q":0.0,"rh":100,"sky":"night","temp":2.1,"time":"06:00","wind":21.3},{"alt":null,"cloud":100,"high":95,"iso":"2026-01-26T05:00Z","label":"unusable","low":100,"mid":100,"moon_alt":-30,"precip":2.1,"q":0.0,"rh":100,"sky":"nautical twilight","temp":2.3,"time":"07:00","wind":24.5}],"peak_quality":0.0,"peak_sky":1.0,"quality_hours":0.0,"reasons":["cloud cover cost 10.0 quality-hours","daylight and twilight cost 2.5 quality-hours","moonlight cost 1.7 quality-hours"],"reference_hours":4.0,"score":0,"score_astronomy":100,"score_weather":0,"sky_hours":9.96,"verdict":"unusable","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2026-01-26T05:40Z","end_local":"07:40","hours":14.25,"label":"unusable","mean_quality":0.0,"start":"2026-01-25T15:25Z","start_local":"17:25"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":100,"dark":false,"high":100,"local":"17:00","low":78,"mid":21,"precip":0.0,"rh":99,"temp":0.5,"time":"2026-01-25T15:00Z","wind":10.0},{"cloud":100,"dark":false,"high":96,"local":"18:00","low":100,"mid":1,"precip":0.0,"rh":100,"temp":-0.1,"time":"2026-01-25T16:00Z","wind":10.4},{"cloud":100,"dark":false,"high":100,"local":"19:00","low":100,"mid":0,"precip":0.0,"rh":99,"temp":0.1,"time":"2026-01-25T17:00Z","wind":12.3},{"cloud":100,"dark":true,"high":100,"local":"20:00","low":100,"mid":0,"precip":0.0,"rh":98,"temp":0.3,"time":"2026-01-25T18:00Z","wind":10.7},{"cloud":100,"dark":true,"high":100,"local":"21:00","low":100,"mid":2,"precip":0.0,"rh":96,"temp":0.8,"time":"2026-01-25T19:00Z","wind":12.6},{"cloud":100,"dark":true,"high":100,"local":"22:00","low":100,"mid":5,"precip":0.0,"rh":95,"temp":2.0,"time":"2026-01-25T20:00Z","wind":17.1},{"cloud":100,"dark":true,"high":77,"local":"23:00","low":100,"mid":20,"precip":0.1,"rh":96,"temp":2.2,"time":"2026-01-25T21:00Z","wind":16.6},{"cloud":100,"dark":true,"high":50,"local":"00:00","low":100,"mid":51,"precip":0.2,"rh":100,"temp":1.9,"time":"2026-01-25T22:00Z","wind":15.3},{"cloud":100,"dark":true,"high":65,"local":"01:00","low":100,"mid":27,"precip":0.2,"rh":100,"temp":1.8,"time":"2026-01-25T23:00Z","wind":15.8},{"cloud":100,"dark":true,"high":99,"local":"02:00","low":100,"mid":64,"precip":0.2,"rh":99,"temp":1.6,"time":"2026-01-26T00:00Z","wind":12.1},{"cloud":100,"dark":true,"high":98,"local":"03:00","low":100,"mid":50,"precip":0.6,"rh":100,"temp":1.7,"time":"2026-01-26T01:00Z","wind":13.6},{"cloud":100,"dark":true,"high":13,"local":"04:00","low":100,"mid":30,"precip":0.3,"rh":100,"temp":1.8,"time":"2026-01-26T02:00Z","wind":15.7},{"cloud":100,"dark":true,"high":33,"local":"05:00","low":100,"mid":54,"precip":0.4,"rh":100,"temp":1.6,"time":"2026-01-26T03:00Z","wind":19.3},{"cloud":100,"dark":true,"high":97,"local":"06:00","low":100,"mid":95,"precip":0.9,"rh":100,"temp":2.1,"time":"2026-01-26T04:00Z","wind":21.3},{"cloud":100,"dark":false,"high":95,"local":"07:00","low":100,"mid":100,"precip":2.1,"rh":100,"temp":2.3,"time":"2026-01-26T05:00Z","wind":24.5},{"cloud":100,"dark":false,"high":91,"local":"08:00","low":100,"mid":100,"precip":1.7,"rh":98,"temp":2.6,"time":"2026-01-26T06:00Z","wind":23.4}],"forecast_source":"history","forecast_updated_at":"2026-10-17T10:38:16Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2026-01-25T17:04:03Z","dark_hours":10.97,"dark_to":"2026-01-26T04:02:27Z","moon":{"illumination":0.47,"phase":"first quarter","waxing":true},"moon_free_dark_hours":5.18,"moonrise":"2026-01-26T09:14:13Z","moonset":"2026-01-25T22:50:35Z","sunrise":"2026-01-26T05:38:48Z","sunset":"2026-01-25T15:27:29Z","twilight":{"astronomical":{"end":"2026-01-25T17:04:03Z","start":"2026-01-26T04:02:27Z"},"civil":{"end":"2026-01-25T15:57:27Z","start":"2026-01-26T05:08:55Z"},"nautical":{"end":"2026-01-25T16:31:09Z","start":"2026-01-26T04:35:17Z"}},"window_end":"2026-01-26T10:00:00Z","window_start":"2026-01-25T10:00:00Z"},"night_date":"2026-01-25","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}