StarCast · Milky Way Forecast

Milky Way Forecast App

StarCast scores Milky Way conditions using moon phase, Bortle class, atmospheric transparency, and cloud cover — and alerts you when a good night is coming so you can plan ahead.

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iOS app: $2.99/mo · 7-day free trial · Cancel anytime

Photography-specific forecasts

Every Variable That Determines a Good Milky Way Night

Milky Way photography is the most condition-dependent type of photography there is. Moon phase, light pollution, transparency, cloud cover, and dark window timing all have to align. StarCast tracks all of them together and tells you when they do.

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New Moon Windows

The galactic core is only photographable on dark nights — within 5 days of new moon for a full window. StarCast shows moon illumination and position so you know exactly how much dark sky you have and when.

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Bortle Class for Your Location

Light pollution is the fixed ceiling on what's possible. Bortle 3 or better is needed for serious Milky Way photography. StarCast shows Bortle class for any location worldwide alongside the live weather score.

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Atmospheric Transparency

A clear sky with high humidity or wildfire smoke still produces flat, washed-out Milky Way images. StarCast factors transparency into every score — because visually clear and photographically clear aren't always the same thing.

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Galactic Core and Dark Window

When the galactic core is above the horizon, when astronomical twilight ends, when the moon sets — the usable window is the overlap of all three. StarCast calculates this for your location each night.

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StarCast Push Alerts

Set your location and minimum score once. StarCast monitors moon phase, cloud cover, and transparency nightly and sends a push alert when a high-scoring Milky Way window is forecast. Stop checking every night manually. Exclusive to the iOS app.

Common Questions

What is the best Milky Way forecast app?

LightCast StarCast. It scores moon phase, Bortle class, atmospheric transparency, and cloud cover into a single 0–100 night sky score. Push alerts notify you when a good Milky Way night is forecast. Free on web, alerts in the iOS app.

How far in advance can I predict Milky Way conditions?

Moon phase: months ahead. Cloud cover: reliably 3–5 days. Transparency: 24–48 hours. Use moon phase to pick target dates, confirm weather 3–5 days out, make final go/no-go 24–48 hours before using StarCast.

What Bortle class do I need for Milky Way photography?

Bortle 3 or better for serious photography. Bortle 1–2 for the most dramatic results. Most designated Dark Sky Parks in the US are Bortle 2. StarCast shows Bortle class for any location.

When is Milky Way season?

May through August in the Northern Hemisphere, with the galactic core highest in June and July. Target new moon windows within this range for the best conditions. StarCast scores conditions for any date.

What else is in LightCast?

Six tools: StarCast, GoldCast, DroneCast, CloudCast, FogCast, and TriCast. $2.99/month after a 7-day free trial.

Know when the next good Milky Way night is coming.

Moon phase · Bortle class · Transparency · Dark window
Push alerts · Saved locations · 3-day outlook

Download LightCast for iOS

Check tonight's Milky Way conditions free →

$2.99/mo after 7-day free trial · Cancel anytime in App Store