Is the sky clear tonight for stargazing? Free forecast with a 0–100 Tonight score: cloud layers, dew risk, transparency, dark windows, and a 7-night outlook.
Frequently asked questions
What humidity is best for stargazing in Guyana?
Lower humidity and a wider temperature-to-dew-point spread reduce fog and dew risk. Tropical nights can still be usable, but saturated air often softens stars and wets optics faster than dry climates. This tool scores dew risk and prefers drier hours for the best window.
What does transparency mean here?
Transparency is estimated from CAMS aerosol optical depth via Open-Meteo’s open Air Quality API. It describes haze, not telescope seeing (arcsecond FWHM). Low AOD means a clearer line of sight.
Is this a replacement for a general weather app?
No. It filters forecast data for astronomy: cloud layer trends, humidity/dew risk, transparency, and when a usable dark window might open. Pair it with the Dark Sky Window tool for moonless darkness timing.
How far ahead should I check?
The 7-night outlook is for planning; treat tonight and tomorrow as the most reliable. Tropical convection can change quickly, refresh before you leave.