Daily stargazing alerts
Should you go outside tonight?
Enter your city to see tonight's score
How the score works
60% weight
Cloud cover
Averaged over the whole dark window, layer by layer. Low cloud blocks everything; thin high cirrus still lets bright stars through.
40% weight
Moon darkness
A new moon boosts the score. A bright Moon only costs points while it is actually above the horizon in the dark hours, and more the higher it stands.
How it actually works
Behind the score
The 60/40 split above is the headline. The full version covers the dark window (sun −18°), the visibility gate, and how the Moon's real altitude sets the penalty — with a worked example from a real forecast run.
Read the methodology →