StarCast · Tonight's Sky

Is It Going to Be Clear Tonight for Stargazing?

Cloud cover is only one variable. Moon phase, transparency, and Bortle class all determine whether tonight is actually worth going out for. StarCast scores all four together for your location.

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Photography forecast

Cloud Cover Alone Doesn't Answer the Question

A standard weather app showing 0% cloud cover doesn't tell you whether tonight will be good for stargazing. A clear sky with a full moon, high humidity, or heavy light pollution can still be a disappointing night. StarCast scores the complete picture.

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Cloud Cover: The Starting Point

No cloud cover is required — but it's just the entry condition, not the full story. Even 10% cloud in the wrong place can obscure the galactic core at the wrong moment. StarCast shows cloud cover hourly so you can see whether the clear window aligns with your shooting window.

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Moon Phase: Often the Real Problem

A bright moon illuminates the sky enough to wash out faint stars even on a perfectly clear night. Full moon is worse for stargazing than light cloud on a new moon night. StarCast shows moon illumination and whether it's above the horizon during your window.

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Transparency: The Hidden Variable

High humidity, wildfire smoke, and aerosols scatter light and reduce star brightness on nights that look visually clear. You can't see poor transparency by looking up — it only shows in the data. StarCast factors transparency into every score.

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Bortle Class: Your Location's Ceiling

Light pollution sets the maximum darkness possible at your location regardless of weather. A clear, moonless, high-transparency night in Bortle 6 is still worse than a slightly hazy new moon night in Bortle 2. StarCast shows Bortle class for any location.

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StarCast Push Alerts

Set your location and score threshold once. StarCast monitors all four variables nightly and sends a push alert when conditions are worth going out. Stop checking manually every evening. Exclusive to the iOS app.

Common Questions

How do I know if it will be clear enough for stargazing tonight?

Check StarCast — it scores cloud cover, moon phase, transparency, and Bortle class together into a single 0–100 night sky score. Above 70 is a strong night. Below 40 is poor. Free on web, push alerts in the iOS app.

Does cloud cover percentage tell me if stargazing will be good?

Not on its own. Moon phase and transparency matter as much as cloud cover. A 0% cloud cover night with a full moon is worse than 20% cloud on a new moon night with excellent transparency.

What is a good StarCast score for stargazing?

Above 70 is an excellent night. 50–70 is decent. Below 40 is generally not worth the effort of driving to a dark sky location. The score accounts for cloud, moon, transparency, and Bortle class together.

Can I see stars through thin cloud?

Sometimes. Thin high cirrus reduces contrast but still allows bright stars and planets through. Low stratus blocks everything. StarCast separates cloud by altitude layer so you can see whether the cloud is thin and high or thick and low.

What is LightCast StarCast?

StarCast scores night sky conditions using moon phase, Bortle class, atmospheric transparency, and cloud cover for any location. Push alerts notify you when a high-scoring night is forecast. Free on web at lightcastsuite.com/starcast, push notifications in the LightCast iOS app. $2.99/month after a 7-day free trial.

One score. Clear answer for tonight.

Cloud cover · Moon phase · Transparency · Bortle class
Push alerts · Saved locations · 3-day outlook

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