{"assessment":{"best_window":{"end":"2026-05-23T23:00Z","end_local":"02:00","hours":0.83,"label":"good","mean_quality":0.61,"start":"2026-05-23T22:10Z","start_local":"01:10"},"cost":{"altitude":0.0,"clouds":2.79,"darkness":3.08,"moon":1.23},"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":88,"high":82,"iso":"2026-05-23T18:00Z","label":"unusable","low":31,"mid":10,"moon_alt":53,"precip":0.1,"q":0.0,"rh":98,"sky":"civil twilight","temp":6.8,"time":"21:00","wind":8.9},{"alt":null,"cloud":56,"high":45,"iso":"2026-05-23T19:00Z","label":"poor","low":14,"mid":7,"moon_alt":46,"precip":0.0,"q":0.12,"rh":99,"sky":"astronomical twilight","temp":6.3,"time":"22:00","wind":7.4},{"alt":null,"cloud":43,"high":27,"iso":"2026-05-23T20:00Z","label":"marginal","low":22,"mid":0,"moon_alt":36,"precip":0.0,"q":0.34,"rh":98,"sky":"night","temp":5.9,"time":"23:00","wind":8.3},{"alt":null,"cloud":33,"high":30,"iso":"2026-05-23T21:00Z","label":"marginal","low":5,"mid":0,"moon_alt":26,"precip":0.0,"q":0.43,"rh":98,"sky":"night","temp":5.8,"time":"00:00","wind":8.4},{"alt":null,"cloud":16,"high":6,"iso":"2026-05-23T22:00Z","label":"marginal","low":10,"mid":0,"moon_alt":15,"precip":0.0,"q":0.6,"rh":98,"sky":"night","temp":5.6,"time":"01:00","wind":9.1},{"alt":null,"cloud":35,"high":13,"iso":"2026-05-23T23:00Z","label":"marginal","low":23,"mid":16,"moon_alt":4,"precip":0.0,"q":0.47,"rh":97,"sky":"night","temp":5.5,"time":"02:00","wind":9.7},{"alt":null,"cloud":95,"high":9,"iso":"2026-05-24T00:00Z","label":"unusable","low":93,"mid":34,"moon_alt":-7,"precip":0.3,"q":0.0,"rh":96,"sky":"night","temp":5.2,"time":"03:00","wind":5.5},{"alt":null,"cloud":88,"high":30,"iso":"2026-05-24T01:00Z","label":"unusable","low":54,"mid":70,"moon_alt":-18,"precip":1.3,"q":0.0,"rh":97,"sky":"astronomical twilight","temp":5.5,"time":"04:00","wind":6.2},{"alt":null,"cloud":43,"high":24,"iso":"2026-05-24T02:00Z","label":"poor","low":24,"mid":1,"moon_alt":-27,"precip":0.5,"q":0.08,"rh":98,"sky":"nautical twilight","temp":5.2,"time":"05:00","wind":6.7}],"peak_quality":0.63,"peak_sky":1.0,"quality_hours":2.15,"reasons":["daylight and twilight cost 3.1 quality-hours","cloud cover cost 2.8 quality-hours","moonlight cost 1.2 quality-hours"],"reference_hours":4.0,"score":44,"score_astronomy":100,"score_weather":44,"sky_hours":4.94,"verdict":"marginal","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2026-05-23T19:00Z","end_local":"22:00","hours":1.33,"label":"unusable","mean_quality":0.0,"start":"2026-05-23T17:40Z","start_local":"20:40"},{"end":"2026-05-23T20:00Z","end_local":"23:00","hours":1.0,"label":"poor","mean_quality":0.15,"start":"2026-05-23T19:00Z","start_local":"22:00"},{"end":"2026-05-23T22:10Z","end_local":"01:10","hours":2.17,"label":"marginal","mean_quality":0.41,"start":"2026-05-23T20:00Z","start_local":"23:00"},{"end":"2026-05-23T23:00Z","end_local":"02:00","hours":0.83,"label":"good","mean_quality":0.61,"start":"2026-05-23T22:10Z","start_local":"01:10"},{"end":"2026-05-23T23:20Z","end_local":"02:20","hours":0.33,"label":"marginal","mean_quality":0.47,"start":"2026-05-23T23:00Z","start_local":"02:00"},{"end":"2026-05-24T00:00Z","end_local":"03:00","hours":0.67,"label":"good","mean_quality":0.61,"start":"2026-05-23T23:20Z","start_local":"02:20"},{"end":"2026-05-24T02:00Z","end_local":"05:00","hours":2.0,"label":"unusable","mean_quality":0.0,"start":"2026-05-24T00:00Z","start_local":"03:00"},{"end":"2026-05-24T02:25Z","end_local":"05:25","hours":0.42,"label":"poor","mean_quality":0.08,"start":"2026-05-24T02:00Z","start_local":"05:00"},{"end":"2026-05-24T02:55Z","end_local":"05:55","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2026-05-24T02:25Z","start_local":"05:25"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":79,"dark":false,"high":57,"local":"20:00","low":42,"mid":20,"precip":0.4,"rh":92,"temp":8.2,"time":"2026-05-23T17:00Z","wind":8.1},{"cloud":88,"dark":false,"high":82,"local":"21:00","low":31,"mid":10,"precip":0.1,"rh":98,"temp":6.8,"time":"2026-05-23T18:00Z","wind":8.9},{"cloud":56,"dark":false,"high":45,"local":"22:00","low":14,"mid":7,"precip":0.0,"rh":99,"temp":6.3,"time":"2026-05-23T19:00Z","wind":7.4},{"cloud":43,"dark":true,"high":27,"local":"23:00","low":22,"mid":0,"precip":0.0,"rh":98,"temp":5.9,"time":"2026-05-23T20:00Z","wind":8.3},{"cloud":33,"dark":true,"high":30,"local":"00:00","low":5,"mid":0,"precip":0.0,"rh":98,"temp":5.8,"time":"2026-05-23T21:00Z","wind":8.4},{"cloud":16,"dark":true,"high":6,"local":"01:00","low":10,"mid":0,"precip":0.0,"rh":98,"temp":5.6,"time":"2026-05-23T22:00Z","wind":9.1},{"cloud":35,"dark":true,"high":13,"local":"02:00","low":23,"mid":16,"precip":0.0,"rh":97,"temp":5.5,"time":"2026-05-23T23:00Z","wind":9.7},{"cloud":95,"dark":true,"high":9,"local":"03:00","low":93,"mid":34,"precip":0.3,"rh":96,"temp":5.2,"time":"2026-05-24T00:00Z","wind":5.5},{"cloud":88,"dark":false,"high":30,"local":"04:00","low":54,"mid":70,"precip":1.3,"rh":97,"temp":5.5,"time":"2026-05-24T01:00Z","wind":6.2},{"cloud":43,"dark":false,"high":24,"local":"05:00","low":24,"mid":1,"precip":0.5,"rh":98,"temp":5.2,"time":"2026-05-24T02:00Z","wind":6.7},{"cloud":45,"dark":false,"high":18,"local":"06:00","low":32,"mid":1,"precip":0.0,"rh":97,"temp":5.1,"time":"2026-05-24T03:00Z","wind":8.1}],"forecast_source":"history","forecast_updated_at":"2026-10-13T18:24:25Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2026-05-23T19:42:29Z","dark_hours":5.17,"dark_to":"2026-05-24T00:52:54Z","moon":{"illumination":0.549,"phase":"waxing gibbous","waxing":true},"moon_free_dark_hours":1.55,"moonrise":"2026-05-23T09:57:31Z","moonset":"2026-05-23T23:18:51Z","sunrise":"2026-05-24T02:53:52Z","sunset":"2026-05-23T17:41:31Z","twilight":{"astronomical":{"end":"2026-05-23T19:42:29Z","start":"2026-05-24T00:52:54Z"},"civil":{"end":"2026-05-23T18:14:08Z","start":"2026-05-24T02:21:15Z"},"nautical":{"end":"2026-05-23T18:55:14Z","start":"2026-05-24T01:40:09Z"}},"window_end":"2026-05-24T09:00:00Z","window_start":"2026-05-23T09:00:00Z"},"night_date":"2026-05-23","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}
