StarsOut
Should you go outside tonight?
Drop everything — go outside
Near-perfect conditions. Nights like this are rare.
Lahti
9.9
out of 10
Peak 2h
10.002:00–04:00
Prime 21–01
9.921:00–01:00
Best this week
8.8Sun, Sep 13
Moon
New Moon
0% lit
Moon doesn’t interfere — perfect darkness
🔭 Moon up: 06:52–19:31
📍 S · 28°
Full moon: Sep 26
Sun ↓ 19:52·Dark from 20:52·13% clouds
Alert me on good nightsSky quality tonight
Best: 02:00–04:00This 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.