Know before you set up the scope.
Hour-by-hour stargazing and astrophotography forecasts for anywhere on Earth. Cloud by layer, transparency, seeing, moonlight and true darkness in one score.
Works anywhere on Earth — 34,000+ named locations and dark-sky sites, or any latitude and longitude.
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What you get
One honest number
Cloud, transparency, seeing, moonlight and true darkness folded into a single 0–100 score for every hour.
Cloud by layer
Low, medium and high cloud forecast separately — because thin cirrus and a low overcast are not the same night.
The window that matters
We tell you when to go out and when to pack up, not just a daily average.
Moon and darkness
Astronomical twilight and moon altitude computed exactly for your coordinates, not your time zone.
Dark-sky observing sites
- Cherry Springs State Park Pennsylvania
- Death Valley National Park California
- Great Basin National Park Nevada
- Natural Bridges National Monument Utah
- Big Bend National Park Texas
- Kitt Peak National Observatory Arizona
- Mauna Kea Hawaii
- Bryce Canyon National Park Utah
- Joshua Tree National Park California
- Grand Canyon National Park Arizona
- Arches National Park Utah
- Canyonlands National Park Utah
- Capitol Reef National Park Utah
- Chaco Culture National Historical Park New Mexico
- Cosmic Campground New Mexico
- Acadia National Park Maine
- Katahdin Woods and Waters Maine
- Headlands International Dark Sky Park Michigan
Observing towns
- Flagstaff Arizona
- Tucson Arizona
- Bend Oregon
- Boulder Colorado
- Reno Nevada
- Santa Fe New Mexico
- Bozeman Montana
- Anchorage Alaska
- Calgary Alberta
- Kelowna British Columbia
- Exeter United Kingdom
- Inverness United Kingdom
- Galway Ireland
- Tromsø Norway
- Rovaniemi Finland
- Reykjavík Iceland
- Kiruna Sweden
- La Serena Chile
- Alice Springs Northern Territory
- Windhoek Namibia
- Queenstown United Kingdom
- Nelson United Kingdom