Astro weather
An hourly observing forecast: cloud cover by layer, winds aloft, dew point and a single 0–100 night score — same as the AstroTools app.
Coming nights
Hourly forecast
Cloud layers
How to read this forecast
The night score folds cloud cover, humidity, winds at several altitudes, dew point and visibility into one 0–100 number, then penalises it for a bright Moon and a sky that never gets fully dark — twilight and white nights. 80+ is a superb deep-sky night; 40–60 still works for the Moon and planets.
The exact same algorithm runs in the AstroTools app — with the forecast always in your pocket, an interactive cloud map, clear-night notifications, ISS passes and a meteor-shower calendar.
Plan your observing with AstroTools
Weather, the Moon, light pollution and satellite passes — in one app.