Aurora Forecast
A live aurora forecast built from real satellite data — the KP index, the interplanetary magnetic field (Bz), solar wind speed and density — so you can see how likely the northern lights are right now, and how the night is shaping up.
Open the live tracker →What drives the aurora forecast
The aurora is powered by the solar wind hitting Earth's magnetic field. A good forecast watches a handful of numbers together — no single value tells the whole story. AuroraSignal reads them live from the SOLAR-1, ACE and GOES spacecraft and folds them into one simple 0–9 “Aurora Power” score.
KP index
The global gauge of geomagnetic activity, 0–9. KP 5+ means a geomagnetic storm and aurora pushing to lower latitudes. KP index →
Bz (IMF)
The north–south tilt of the Sun's magnetic field. A strongly southward Bz cracks the door open and lets energy pour in. Bz & solar wind →
Solar wind
Speed and density of the particle stream from the Sun. Faster, denser wind hits harder and lifts aurora chances. Solar wind →
Aurora Power
Our single 0–9 score fusing Bz, Bt, speed and density — the quick read on whether it's worth heading out tonight. See it live →
How to read tonight's aurora forecast
Three things line up on the best nights. First, Bz turns sharply south (negative, ideally below −10 nT) and stays there. Second, the solar wind speed climbs above ~500 km/s, often after a coronal hole or a CME arrival. Third, the KP index rises to 5 or more, meaning the auroral oval is expanding toward you. When all three agree, the Aurora Power score jumps — that's your cue to find a dark spot away from city lights and look north.
Where and when to look
Aurora is easiest to catch under a clear, dark sky in the hours around local midnight, away from light pollution. Even a modest storm can bring the lights to mid-latitudes when Bz stays strongly southward for hours.
Tonight
Is it worth going out after dark? Northern lights tonight →
Aurora map
Where the oval glows around the pole right now. Aurora map →
Alerts
Get a heads-up when a storm ramps up. Aurora alerts →
Aurora forecast FAQ
How accurate is an aurora forecast?
Short-term forecasts (the next 30–60 minutes) are the most reliable, because they use solar wind measured just upstream of Earth by spacecraft at the L1 point. Day-ahead forecasts are more uncertain — they depend on predicting solar activity that hasn't reached Earth yet.
What KP index do I need to see the aurora?
It depends on your latitude. Far north (Norway, Iceland, northern Canada) can see aurora at KP 2–3. Mid-latitudes usually need KP 5+ (a geomagnetic storm) for a good chance. Learn about the KP index →
Why does Bz matter so much?
Bz is the north–south component of the Sun's magnetic field carried by the solar wind. When it points south it links up with Earth's field and lets solar energy flow in — the single biggest switch for aurora. More on Bz →
See the aurora forecast live
Real-time KP index, Bz, solar wind and a single 0–9 Aurora Power score — updated every minute from satellite data.
Open the live tracker →