StarsOutAlert me on good nights
Should you go outside tonight?
Probably not tonight
Too much cloud cover for a good session.
San Francisco
4.3
out of 10
Peak 2h
5.620:00–22:00
Prime 21–01
4.421:00–01:00
Best this week
9.1Sat, Sep 5
Moon
Waning Gibbous
91% lit
Very bright — stick to planets and the moon itself
🔭 Moon up: 20:50–10:21
Full moon: Sep 26
Sun ↓ 19:41·Dark from 20:41·72% clouds
🔭
Moon visible today
06:39 – 08:35 · 91% lit · great for telescope viewing
Next great night
Wednesday — 8.0
✨ Great night tonight
Sky quality tonight
Best: 20:00–22:00This 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.