Will the sky be clear tonight?
ClearSkys tells you whether tonight's sky will be clear enough to stargaze. We analyse cloud cover, moon, wind and humidity for your exact location and score it out of 100, with the best clear-sky window picked out hour by hour. Open the full forecast for hour-by-hour scores, planet visibility windows, ISS passes, a complete score breakdown and observer profiles for visual, astrophotography and planetary observing.
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Go out tonight
A clear sky forecast built for stargazers
A regular weather app tells you if it'll rain. It won't tell you whether the sky will actually be clear enough to see anything or when tonight's clearest window opens. ClearSkys is built for exactly that: it pulls the cloud, moon, wind and humidity data for wherever you are and turns it into one honest answer about whether tonight is good for stargazing.
Check whether the sky is clear tonight, see which planets are visible tonight and tonight's aurora chances, and browse stargazing forecasts by location for the next genuinely clear night worth planning around. It works anywhere in the world.
What we analyse
Eight factors decide whether a night is worth it. We weigh them all so you don't have to.
Cloud Cover
Three-layer analysis (low, mid, high) with per-profile weighting. Thin cirrus that ruins astrophotography barely bothers planetary viewing.
Transparency
Haze and aerosols dim the sky without showing up as cloud. Hourly visibility folds into the clarity score.
Seeing
Jet-stream wind at 250 hPa, the standard proxy. A roaring jet turns planets to mush at high magnification.
Moonlight
Illumination, altitude and rise/set times, weighted for how much a bright moon washes out your targets.
Dew Risk
Dew-point spread tracked hour by hour. Under 2°C and your optics start fogging; the score warns you first.
Wind
Wind shakes the scope and ruins seeing. We flag when it's too gusty for high-magnification work.
Rain Probability
Even a 30% chance of rain means you might not want to risk the gear. We weight it into the score.
Best Window
The single longest run of clear, dark hours, picked out so you know exactly when to head out.
How the score works
Every night is scored 0–100 from the eight factors above, then adjusted for moonlight and twilight. The single best run of clear, dark hours is picked out so you know exactly when to go.
Tune it to how you observe
Switch profiles and the same night is re-scored for what you actually do, or build your own.
Balanced scoring for all-round stargazing. The best starting point.
Clear skies and dry optics weighted hardest; thin cirrus and moonlight penalised more.
Forgiving for binoculars or naked-eye. Rain and dew matter more, moon less.
Seeing from the jet stream drives the score; thin cloud and moon barely matter.
Blends sky conditions with expected aurora activity for your latitude.
Not happy with the presets? Score the sky your way.
Decide exactly what counts. Weight cloud, wind, humidity, rain and seeing however you like, drop anything you don't care about to zero. Go further and set how much low, mid and high cloud each matter, so thin cirrus ruins a deep-sky night but barely dents a planetary one. Your profile saves to your device, or your account if you're signed in.
Build your custom score →Tonight's highlights
What's happening in the sky, for your location.
Showing Brisbane · highlights update with your location, and only appear when there's genuinely something to see.
Stargazing forecasts by location
Browse tonight's conditions for cities and dark-sky sites worldwide.
See tonight's scores for every location on the map →
Stargazing guides
Learn how to read the sky and get the most from every clear night.