StarsOutAlert me on good nights
Should you go outside tonight?
Might be worth a look
Partial clearing expected. Keep an eye out.
Rio de Janeiro
4.8
out of 10
Peak 2h
6.400:00–02:00
Prime 21–01
4.821:00–01:00
Best this week
8.9Thu, Sep 3
Moon
Waning Gibbous
91% lit
Very bright — stick to planets and the moon itself
🔭 Moon up: 19:09–07:21
📍 NW · 48°
Full moon: Sep 26
Sky now
Clear · 0%
Measured at SBRJ · 1km away · 35min ago
Sun ↓ 17:42·Dark from 18:42·72% clouds
🔭
Moon visible today
06:04 – 08:35 · 91% lit · great for telescope viewing
Next great night
Wednesday — 7.8
✨ Great night tonight
Sky quality tonight
Best: 00:00–02:00This week’s nights
America/Sao PauloHow 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.