Stargazing Forecast
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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.

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Free · No sign-up · Works for any location on Earth

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

Six factors decide whether a night is worth it. We weigh them all so you don't have to.

☁️ Cloud Cover
The biggest factor. Three-layer analysis (low, mid, high) — because thin high cloud and thick low stratus are very different beasts.
🌙 Moon Phase
A bright moon washes out faint targets. We calculate illumination, rise/set times, and how much it affects your specific session.
💨 Wind Speed
Wind shakes the scope and ruins seeing. We flag when it's too gusty for high-magnification work.
💧 Humidity
High humidity fogs optics and kills transparency. We track it hourly so you know when dew becomes a problem.
🌧️ 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
Conditions change hour by hour. We find the best consecutive run of clear, calm sky so you know exactly when to go out.

One Score, Clear Answer

Everything rolls up into a single score. No need to cross-reference three weather apps, a moon calendar, and a cloud chart. Just check your score.

80+ Excellent 65–79 Good 45–64 Mixed <45 Poor

Plus, While You're Out There

Beyond the go/no-go decision, we tell you what's worth looking at tonight.

Planets
Visible tonight
Altitude & direction for each
Satellites
ISS & bright passes
Exact pass times overhead
Aurora
Alerts for your latitude
Kp & Ovation, location-aware
Meteors
Active showers
Peak nights & expected rate
Forecast
7 nights ahead
Plan around the weather
Alerts
Push when skies clear
We message, you observe

Stargazing Forecasts by Location

Tonight's conditions for 100+ cities, or search any location.

Stargazing Guides

Learn how stargazing conditions work, what to look for, and how to read a forecast.

Frequently Asked Questions

How do I know if the sky will be clear tonight?

Enter your location and ClearSkys shows you tonight's cloud cover hour by hour, alongside moon, wind and humidity, rolled into a single clear-sky score from 0 to 100. A high score means clear, settled skies worth getting out for; a low one means stay in. You'll also see the clearest window of the night, so you know exactly when to look up.

How does the stargazing score work?

Cloud cover is the biggest factor — if you can't see through it, nothing else matters. After that, wind (shakes the scope), humidity (fogs the optics), rain probability, and moon illumination are all weighted into a single 0–100 score. Above 80 is Excellent, 65–79 Good, 45–64 Mixed, below 45 Poor.

What planets are visible tonight?

ClearSkys calculates which planets are above the horizon during darkness hours at your exact location, showing peak altitude and direction. No more guessing whether Jupiter is up — you'll know exactly where to point.

Can I get alerts when conditions are good?

Yes — free push notifications alert you when tonight's score crosses your threshold at saved locations. Also fires for aurora activity. No app install needed — works straight from your browser.

Does ClearSkys work worldwide?

Yes — enter any location on Earth. Weather data comes from Open-Meteo's global coverage, and all astronomy calculations (sun, moon, planets, satellites, aurora) are computed for your exact coordinates.