Check tonight's stargazing forecast
Hour-by-hour forecasts for the night sky: cloud at every altitude, the Moon, the ISS and how dark it'll get, so you're out when it's worth it.
Free download · No account required
Available on iPhone, iPad & Apple Watch.
Tonight's Moon
Waning Crescent
5% illuminated · waning
- New Moon Mon, Nov 9
- First Quarter Tue, Nov 17
- Full Moon Tue, Nov 24
- Last Quarter Tue, Dec 1
Moon direction in popular cities
Everything for a night under the stars
Know when it'll be clear, where the Moon will be, when the ISS flies over and where the darkest sky is, before you leave the house.
Free in Starglow
48-hour sky forecast
. Total, low, mid and high cloud, visibility and precipitation for every hour, lined up with sunlight, the Moon and ISS passes on one scrolling timeline.Moon map & AR
. Where the Moon rises and sets, and where it is right now, on a compass over the map, and its path through your camera. Try it on the web.Alerts
. Dark skies, moonrise and moonset, new and full Moons, and ISS passes, timed for the place you're watching.
ISS passes
. Visible passes sit on the forecast with how high they climb, so you can see whether a bright evening pass lines up with a clear sky.With Starglow Pro
Vantage Point
. Stand anywhere on the map and see the real terrain and buildings with the Moon, stars, planets, the Milky Way and ISS passes where they'll be, on screen or in AR.
Dark Site Finder
. Light pollution from NASA satellite data, your sky's Bortle class, and the darkest places nearby ranked by tonight's cloud.
Star Trails
. Pick how long the shutter stays open and see every star's arc over the real skyline, and whether twilight, the Moon or an ISS pass will cross the frame.Seeing
1.4″
Steady air for planets
Transparency
Excellent
Clear air for galaxies
Models Clear
6/6
Six weather models agree
Seeing, transparency & forecast confidence
. How steady and how clear the air will be, hour by hour, and how many of six independent weather models forecast a clear sky.“For each hour of the day it shows the suns and moon brightness and how the weather and cloud cover factor into being able to see or not see the stars and planets and other objects in the sky.”
Frequently asked questions
Everything you need to know about Starglow.
What is Starglow?
Starglow is a stargazing and astrophotography forecast app. It shows, hour by hour, whether the sky will be clear and dark: cloud at every altitude, visibility, sunlight and twilight, the Moon, and ISS passes, plus a Moon map with AR, alerts, and, with Starglow Pro, tools like Vantage Point, Star Trails and the Dark Site Finder.
Is Starglow free?
Yes. The 48-hour sky forecast, the Moon map and AR, alerts, Siri & Shortcuts, red night mode and sun and moon times are free. Starglow Pro adds 5-day forecasts, seeing and transparency, forecast confidence, the Dark Site Finder, Best Location Tonight, the 3D map, Vantage Point, Star Trails, ISS passes in AR, widgets and saved locations.
How accurate are the forecasts?
Forecasts come from high-resolution weather models updated hourly. With Pro, the Models Clear row shows how many of six independent weather models forecast a clear sky each hour, so you can see how much to trust tonight. Moon, sun and ISS times are calculated astronomically.
How does Starglow help me see the Milky Way?
You need astronomical darkness, no Moon and clear skies. The timeline shows all three together, Dark Sky alerts tell you when darkness begins, and the Dark Site Finder points you to the darkest skies nearby. Vantage Point even shows where the Milky Way will be over the real skyline.
Can Starglow tell me when the ISS is visible?
Yes. Visible International Space Station passes appear on the forecast with their brightness and the direction they appear and disappear. You can get an alert ten minutes before a pass, and with Pro, open any pass to see its path across your sky in AR.
What are seeing and transparency?
Seeing is how steady the air is: good seeing keeps planets and fine detail sharp. Transparency is how clear the air is: high transparency brings out faint galaxies and nebulae. Starglow Pro forecasts both, hour by hour.
Will Starglow protect my night vision?
Yes. Red night mode turns the whole app red so you can check it at the eyepiece without losing your dark adaptation.
What devices does Starglow run on?
iPhone (including iPhone Duo) and iPad, with an app for Apple Watch. Widgets are available for the Home and Lock Screen with Pro.
How does Starglow work with Alpenglow?
They are sister apps from the same developer. Alpenglow forecasts how colourful sunrise and sunset will be; Starglow picks up when the sky goes dark.
Download Starglow
Check tonight's sky before you head out.
Available on iPhone, iPad & Apple Watch.