Warning · Geomagnetic Storm · 07:34
Issue Time: 2026 Sep 08 0734 UTC
Aurora tonight
Aurora activity
3.7Kp
Good chance tonight
Peaks at Kp 5.0 around 05:00
Dark from 22:40 to 03:10.
Tonight · Kp by the hourCalmActiveStorm
Kp 5.0
18202200020406
Bt
5.1 nT
Density
7.4 p/cm³
Power
51 GW
Storm
G0
No storm
The nights ahead
Geomagnetic forecast. Seeing it still needs darknessNight to Thursday 10 Sept
3.3Kp
Best window23–04
Some chanceNight to Friday 11 Sept
2.0Kp
Best windowBeyond the forecast
Little chanceSolar wind now
Last hour · DSCOVRBz · field direction−8 … +8 nT
−0.8nTsouthward, favourable
17:0217:2017:3817:56
A southward field opens Earth's magnetic field. Everything below the dashed line helps. Lowest −5.3 nT at 17:19.
Speed465–504 km/s
483km/s
17:0217:2017:3817:56
The auroral oval
NOAA OVATION · 30-minute forecastNorthern hemisphere
OvationLoading
Solar wind in space
WSA-EnlilImage unavailable
The sun now
Coronagraphs and EUVLASCO C2
SOHOImage unavailable
LASCO C3
SOHOImage unavailable
CCOR-1
GOES-19Image unavailable
SUVI 171 Å
GOES-19Image unavailable
Sunspots
SDO HMIImage unavailable
C2 shows the inner corona, C3 the outer. The white streaks are particles hitting the camera.
Alerts
NOAA SWPC · last 24 hoursWarning · Geomagnetic Storm · 05:46
Issue Time: 2026 Sep 08 0546 UTC
Warning · Geomagnetic Storm · 05:45
Issue Time: 2026 Sep 08 0545 UTC
Warning · Geomagnetic Storm · 20:01
Issue Time: 2026 Sep 07 2001 UTC
Understanding the aurora
What is the aurora?
Charged particles from the sun follow Earth's magnetic field down towards the poles and collide with oxygen and nitrogen high in the atmosphere. Those collisions emit light: green from oxygen around 100 km, red higher up, violet from nitrogen.
Why do Bz and solar wind matter?
Bz is the direction of the magnetic field carried by the solar wind. When it points south, meaning negative, it links up with Earth's own field and lets energy in. A strongly southward Bz and a high speed produce aurora even at moderate Kp.
What does the Kp number mean?
Kp measures global geomagnetic disturbance on a scale from 0 to 9. At Sortland, Kp 2–3 is enough for aurora to the north, while Kp 5 and above drags the oval so far south that the light stands directly overhead.
When is the season?
From late August to the middle of April. For the rest of the year the sun sits too high at night. The activity can be just as good, but the sky is too bright for anything to show.