Northern and southern lights forecast
Northern and southern lights tonight: Kp now 3.7, the three-day Kp forecast, the live auroral oval, the best places tonight and the Kp every town needs to see the aurora.
22 Oct, 12:38 UTC
Tonight's best places
Where the oval, the darkness and the clouds come together tonight.
Kp, the next three days
Kp forecast for the next three days
Space-weather messages
The oval right now
Probability of aurora overhead in the next half hour; it is seen low on the horizon up to about 500 km further from the pole. The marked dots show where.
Which Kp do you need?
Countries
Geomagnetic storms since 1932
Every storm that pushed the Kp index to 5 or more since 1932: 5,275 of them, 756 strong (G3 or above) and 23 extreme (G5). Each with its peak, its hours, the Kp every three hours and the places that could see the lights.
Best time of year
Share of days with Kp 5 or more, by month (1996–2025)
Storms are most frequent around the equinoxes (March–April and September–October), when the Earth's magnetic field couples best with the solar wind; in the far north the season is also set by darkness, which disappears from May to July.
How it works
The Kp index measures how disturbed the Earth's magnetic field is, from 0 (quiet) to 9 (extreme storm), in three-hour steps. The stronger the disturbance, the further the auroral oval — the ring of light around each magnetic pole — spreads towards the equator.
What counts is the magnetic, not the geographic, latitude. The magnetic pole lies over northern Canada, so North America sees the lights much further south than Europe or Asia at the same latitude. For every place we compute its magnetic latitude and from it the Kp at which the edge of the oval appears low on the horizon and the Kp at which it is overhead.
You also need true darkness (the sun at least 12° below the horizon — around midsummer there is none in the far north), a clear sky and ideally no bright moon. The monthly odds on each page combine thirty years of measured Kp during the dark hours with the place's usual cloud cover.
Look towards the magnetic pole (the direction shown on each page), away from street lights. Give your eyes 20 minutes to adapt; a phone camera in night mode often shows the colours before the eye does. The best hours are usually the two or three around local midnight.