StarsOut
Should you go outside tonight?
Great night tonight
Clear skies and dark conditions. Go outside.
Tokyo
8.8
out of 10
Peak 2h
9.122:00–00:00
Prime 21–01
8.921:00–01:00
Best this week
8.5Sun, Jul 19
Moon
Waxing Crescent
5% lit
Moon doesn’t interfere — perfect darkness
🔭 Moon up: 06:20–20:26
📍 E · 53°
Full moon: Jul 29
Sun ↓ 18:57·Dark from 19:57·36% clouds
Alert me on good nightsSky quality tonight
Best: 22:00–00:00This 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.