StarsOut
Should you go outside tonight?
Not worth it tonight
Clouds will block the view. Stay inside.
Lahti
0.8
out of 10
Peak 2h
2.801:00–03:00
Prime 21–01
0.021:00–01:00
Best this week
10.0Thu, Jun 18
Moon
Waning Crescent
2% lit
Moon doesn’t interfere — perfect darkness
🔭 Moon up: 01:46–21:50
📍 SE · 41°
Full moon: Jun 29
Sun ↓ 22:52·Dark from 23:52·100% clouds
Alert me on good nightsNext great night
Sunday — 9.0
✨ Great night tonight
Sky quality tonight
Best: 01:00–03:00This week’s nights
Europe/HelsinkiHow 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.