Good to know
Aurora questions, answered
The questions we get asked most about seeing the northern lights — and how our live forecast works. For the deeper science, see the aurora guides.
How does this forecast actually work?
We combine four things in real time: the planetary Kp index from NOAA's Space Weather Prediction Center (how far the auroral oval reaches toward you), whether the sky is dark enough at your location right now, current cloud cover, and how much a bright moon would wash out a faint display. The aurora can be 'active' yet invisible because it's daylight, overcast or moonlit — so all four have to line up.
What is the Kp index?
Kp is a 0–9 scale of global geomagnetic activity. The higher it climbs, the further from the poles the aurora becomes visible. Directly under the oval (Tromsø, Fairbanks) you need almost nothing — Kp 0–2 on a clear, dark night; seeing it from mid-latitudes needs a Kp 6+ storm.
Why does it say 'not visible' when the Kp is high?
Two common reasons. In summer at far-northern latitudes the sky never gets dark enough (the midnight sun), so even a strong storm is invisible. And thick cloud simply blocks the view. We factor both in rather than only showing the space-weather number.
What's the best time of year and night to see the aurora?
Roughly September to March in the north (March to September in the south), during the dark hours around local midnight. You need clear skies and as little light pollution as possible — get away from town lights and let your eyes adjust for 15–20 minutes.
Do I need a tour, or can I see it on my own?
Under the oval you can often see it from anywhere dark. But guided 'chasing' tours exist because they drive you to wherever the sky is clear that night — which dramatically raises your odds on a short trip. A rental car achieves the same if you're comfortable navigating winter roads.
Will my phone camera capture it?
Modern phones in night mode can capture faint aurora the eye barely registers. For sharper results, a camera with manual mode, a fast wide lens and a tripod for multi-second exposures makes a big difference — see our gear guide.