# Night Sky Alert

> One score (0–100) per city, every night: is the sky worth going outside for? Combines aurora odds for both hemispheres (NOAA SWPC Kp + OVATION), rocket launches within view (The Space Devs), meteor shower peaks (AMS dates, adjusted for how high each radiant climbs at your latitude), International Space Station passes (CelesTrak, SGP4), moonlight and MET Norway cloud forecasts. Covers 6,468 cities in 171 countries.

## Key pages
- [Home](https://nightskyalert.com/)
- [How the score works](https://nightskyalert.com/how-the-score-works): exact formula
- [Aurora tonight](https://nightskyalert.com/aurora): northern and southern lights
- [Rocket launches](https://nightskyalert.com/launches)
- [Meteor shower calendar](https://nightskyalert.com/meteor-showers)
- [Space station passes](https://nightskyalert.com/iss)
- [All countries](https://nightskyalert.com/countries)
- City pages: https://nightskyalert.com/tonight/{city-slug} (e.g. https://nightskyalert.com/tonight/london-united-kingdom)
- [Sitemap index](https://nightskyalert.com/sitemap.xml)

## API (JSON, free, cached)
- https://nightskyalert.com/api/tonight/{city-slug}: tonight's score, reasons and inputs
- https://nightskyalert.com/api/best-tonight: top cities right now, worldwide

## Best skies right now
- Umeå, Sweden: 100/100 (Go outside) https://nightskyalert.com/tonight/umea-sweden
- Murmansk, Russia: 96/100 (Go outside) https://nightskyalert.com/tonight/murmansk-russia
- Winnipeg, Manitoba: 89/100 (Go outside) https://nightskyalert.com/tonight/winnipeg-manitoba
- Saskatoon, Saskatchewan: 87/100 (Go outside) https://nightskyalert.com/tonight/saskatoon-saskatchewan
- Bergen, Norway: 77/100 (Go outside) https://nightskyalert.com/tonight/bergen-norway
- Regina, Saskatchewan: 71/100 (Worth a look) https://nightskyalert.com/tonight/regina-saskatchewan
- Edmonton, Alberta: 65/100 (Worth a look) https://nightskyalert.com/tonight/edmonton-alberta
- St. Albert, Alberta: 64/100 (Worth a look) https://nightskyalert.com/tonight/st-albert-alberta
- Sherwood Park, Alberta: 62/100 (Worth a look) https://nightskyalert.com/tonight/sherwood-park-alberta
- Oulu, Finland: 61/100 (Worth a look) https://nightskyalert.com/tonight/oulu-finland
- Calgary, Alberta: 59/100 (Worth a look) https://nightskyalert.com/tonight/calgary-alberta
- Medicine Hat, Alberta: 59/100 (Worth a look) https://nightskyalert.com/tonight/medicine-hat-alberta
- Green Bay, Wisconsin: 58/100 (Worth a look) https://nightskyalert.com/tonight/green-bay-wisconsin
- Sault Ste. Marie, Ontario: 58/100 (Worth a look) https://nightskyalert.com/tonight/sault-ste-marie-ontario
- Oklahoma City, Oklahoma: 57/100 (Worth a look) https://nightskyalert.com/tonight/oklahoma-city-oklahoma

Data credits: NOAA SWPC (public domain; no endorsement implied), MET Norway (CC BY 4.0), The Space Devs, CelesTrak, GeoNames (CC BY 4.0), American Meteor Society, Natural Earth.