How to check your aurora chance
- Type a place or click “My location”.
- Choose camera or naked eye, and how open your view to the north is.
- Check the chance now and the best window tonight. The chance takes Kp, the auroral oval, cloud cover, twilight and the Moon into account.
- Watch Bz and solar wind speed. Bz pointing south (negative) for 15 minutes or more means activity is about to rise.
- When you go out, face the direction shown in “Where to look”, away from city lights.
Questions
What Kp do I need?
It depends on your geomagnetic latitude. Northern Scandinavia sees aurora at Kp 1–2, Scotland and southern Scandinavia at Kp 4–5, central Europe and the northern US at Kp 6–7. The page computes your exact threshold.
Where does the data come from?
Kp, solar wind (DSCOVR/ACE), the OVATION oval, X-rays and alerts come from NOAA SWPC. CMEs from NASA DONKI, cloud cover from Open-Meteo.
What does negative Bz mean?
A southward interplanetary magnetic field connects with Earth’s field and lets energy into the magnetosphere. The lower and longer, the stronger the aurora.
Why does my camera see aurora I cannot?
The sensor collects light for several seconds and records colour. Faint aurora low on the horizon looks like a grey glow to the eye.
How often is the data refreshed?
Solar wind, Kp and the oval every 2 minutes, the forecast and alerts every 10 minutes, CMEs every 30 minutes.
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