StarsOut
Should you go outside tonight?
Drop everything — go outside
Near-perfect conditions. Nights like this are rare.
San Francisco
9.8
out of 10
Peak 2h
9.921:00–23:00
Prime 21–01
9.821:00–01:00
Best this week
8.8Wed, Jul 22
Moon
Waxing Crescent
5% lit
Moon doesn’t interfere — perfect darkness
🔭 Moon up: 08:38–22:20
Full moon: Jul 29
Sky now
Clear · 0%
Measured at KOAK · 18km away · 10min ago
Sun ↓ 20:30·Dark from 21:30·9% clouds
Alert me on good nightsSky quality tonight
Best: 21:00–23:00This week’s nights
America/Los AngelesHow 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.