Aurora forecast tonight
Could the northern or southern lights appear from your location tonight? Here’s the live geomagnetic activity, a quick check for your spot, and a plain-English guide to reading an aurora forecast.
Can you see it from your location?
Pick a place (or use your location) to see the Kp it needs and whether tonight’s forecast measures up.
Reading the live forecast…
How to read an aurora forecast
Three numbers do most of the work — and once they click, any aurora forecast becomes easy to read.
1 · The Kp index (0–9)
Kp is a single global number for how disturbed Earth’s magnetic field is right now. A quiet night is Kp 0–2; a major geomagnetic storm is Kp 7–9. The higher it climbs, the further from the poles the aurora is pushed — so a bigger Kp literally means the lights reach more of the world.
2 · Your latitude & the auroral oval
Aurora forms a ring — the auroral oval — around each geomagnetic pole. What matters is your geomagnetic latitude, not the one on a map: the magnetic pole sits over Arctic Canada, so North America sees the lights further south than Europe at the same map latitude. The stronger the storm, the wider the oval, and the lower the Kp you need is the closer you already are to it. Here’s roughly how far each Kp level carries the lights:
| Kp | Storm | Lights typically reach (clear, dark sky) |
|---|---|---|
| 0–1 | Quiet | Directly over the far north — Arctic Norway, northern Alaska, Iceland |
| 2 | Quiet | Southern Norway, central Sweden & Finland, Anchorage |
| 3 | Unsettled | Scotland, Scandinavia, the Canadian prairies |
| 4 | Active | Northern England, Denmark, Vancouver, the northern Great Lakes |
| 5 | Storm · G1 | Ireland, the Netherlands, the northern US border states |
| 6 | Storm · G2 | Central UK, Germany, Chicago, Boston, Tasmania |
| 7 | Strong · G3 | London, Paris, New York, Oregon, southern NZ |
| 8 | Severe · G4 | Central France, Colorado, Virginia |
| 9 | Extreme · G5 | Mediterranean, Texas, even Florida — very rare (e.g. May 2024) |
Approximate, for a clear and properly dark sky; the lights appear lower and fainter toward the edge of each band.
3 · The other three ingredients
Geomagnetic activity
A solar storm has to push the auroral oval down to your latitude. That push is measured by the Kp index, 0–9 — the higher the number, the further south the lights reach.
Darkness
You need a genuinely dark sky: the Sun well below the horizon, and ideally no bright Moon. Aurora is a year-round phenomenon, but you can only see it in the dark — so autumn through early spring, away from the midnight-sun months.
Clear skies
Aurora glows about 100 km up — well above the clouds. A solid overcast hides it completely, so check the cloud forecast for your night, and chase the gaps.
A dark location & the right direction
Escape town lights and find a clear view toward the pole — north in the northern hemisphere, south in the southern. Lower Kp means the glow sits low on that horizon; higher Kp brings it overhead.
How far ahead can you trust it?
A 3-day Kp outlook (the bars above) is a useful heads-up, not a promise — solar storms are hard to time days out. The reliable call comes only 30–90 minutes ahead, when spacecraft a million miles sunward measure the solar wind just before it reaches Earth. That short-range data feeds NOAA’s OVATION “aurora now” model, which estimates the chance of visible aurora over your head in the next hour. So: watch the multi-day trend to know which nights are worth it, then check the live numbers on the night itself.
Your step-by-step on the night
- Check the Kp forecast. Look at the predicted Kp for your night. NOAA issues a 3-day outlook; the sharper call comes a few hours ahead.
- Find the Kp your latitude needs. Your geomagnetic latitude sets the bar. Use the table below, or the live check above, to see the Kp the lights need to reach you.
- Confirm it will be dark. Make sure the Sun is well down and the Moon isn’t washing out the sky during your viewing window.
- Check the clouds. Pull up an hourly cloud forecast and look for clear breaks over your location.
- Get dark and look poleward. Drive away from city light, let your eyes adapt for 20 minutes, and watch the horizon toward the pole. A phone on a long exposure will reveal colour your eyes can’t.
Aurora forecast — FAQ
Can I see the aurora tonight?
It depends on three things: how strong tonight’s geomagnetic storm is (the Kp index), how far you are from the geomagnetic pole, and whether your sky is dark and clear. Use the live check above for your location, or open Starly for a forecast tuned to your exact spot.
What is a good Kp index for aurora?
There’s no single number — it depends on your latitude. Far-north places like Tromsø see aurora at Kp 0–2 most clear nights. Mid-latitude cities like London or New York need a strong storm, around Kp 7 or higher. The table above shows roughly how far south each Kp level reaches.
How accurate is the aurora forecast?
The 3-day Kp outlook is a rough trend. The reliable, sharp forecast only comes 30–90 minutes ahead, when satellites at the L1 point measure the solar wind just before it hits Earth — that feeds NOAA’s OVATION “aurora now” model. So treat a multi-day forecast as “worth watching,” and check again on the night.
Where should I look for the northern lights?
Toward the nearer pole — north if you’re in the northern hemisphere, south if you’re in the southern. When activity is marginal the aurora sits low on that horizon; in a strong storm it can stand directly overhead or even spread past it.
Does the Moon affect aurora viewing?
A bright Moon won’t stop a strong aurora, but it washes out faint, delicate displays. For the best chance of seeing subtle colour, aim for nights around the new Moon or when the Moon is below the horizon.
What time of night is best?
Activity tends to peak around magnetic midnight — very roughly 10 pm to 2 am local time — though a strong storm can light up the sky at any dark hour.
Get the forecast for your exact sky
Starly works out your geomagnetic latitude, pulls tonight’s Kp, the live oval and your cloud cover, and tells you — in one card — whether to head out. Free, in your browser.
Open the aurora forecast in Starly →