Will the sky be clear tonight? How to read a star forecast
“Will the sky be clear tonight?” is the first question before any night under the stars. A normal weather app answers it badly: it shows one cloud icon for the whole night. A star forecast answers it hour by hour — and tells you when the next clear night is if tonight is cloudy.
Check tonight in 30 seconds
Type your town on the home page or tap your spot on the night sky map. You get a clear sky forecast for every hour of the night and a 0–10 night score. 7 or more means go; 4–6 means a short window or thin cloud; below 4 means stay home or look for the next clear night.
Clear sky forecast: why the cloud layer matters
“40% cloud” can be a great night or a useless one. Thin high cloud (cirrus) only dims faint stars; low cloud blocks everything. That’s why NightSkyCast shows low, mid and high clouds separately and weights low clouds most. A gap of two clear hours between fronts is often enough for the Moon, planets or a quick astrophoto.
When is the next clear night?
Every night report shows the next nights side by side with their scores, so the clearest one stands out. Cloud forecasts are reliable for about 24 hours, so plan with the 3-night view and check again on the day. Save your places and turn on notifications to get a message when a clear night is coming.
Clear is not enough: darkness, Moon, light pollution
A clear sky right after sunset is still bright: real darkness starts with astronomical night, when the Sun is 18° below the horizon. A bright Moon washes out the Milky Way, and in a city (Bortle 7–9) you’ll see a few dozen stars at most. The night score counts all of this — read more in how to choose a night and the Bortle scale.
Is it clear right now?
Choose “Now” in the night report: you’ll see the current cloud cover at your spot and how it changes over the next hours.