StarsOutAlert me on good nights
Should you go outside tonight?
Probably not tonight
Too much cloud cover for a good session.
Osaka
4.5
out of 10
Peak 2h
6.601:00–03:00
Prime 21–01
4.321:00–01:00
Best this week
9.0Sat, Sep 5
Moon
Waning Gibbous
91% lit
Very bright — stick to planets and the moon itself
🔭 Moon up: 19:22–08:19
📍 E · 25°
Full moon: Sep 26
Sky now
Clear · 0%
Measured at RJOO · 12km away · 30min ago
Sun ↓ 18:28·Dark from 19:28·37% clouds
🔭
Moon visible today
05:30 – 08:35 · 91% lit · great for telescope viewing
Next great night
Wednesday — 7.3
🌙 Good night ahead
Sky quality tonight
Best: 01:00–03:00This week’s nights
Asia/TokyoHow the score works
60% weight
Cloud cover
Layer-weighted across the best 2-hour window of the night. Low clouds block everything, thin high cirrus still lets bright stars through.
40% weight
Moon darkness
A new moon boosts the score. A full moon near midnight washes out all but the brightest stars. We ease the penalty after midnight when the moon is setting.