A coronal mass ejection from the M6.7 solar flare of 8 October reached Earth at 14:34 UTC on 10 October, and NOAA reported a strong G3 geomagnetic storm (Kp 7) from 17:58 UTC. Northern lights were photographed across the UK down to England’s south coast and in northern Germany, while Austria was mostly cloudy and we found no confirmed sighting from Türkiye. NOAA kept a G2 watch for 11 October. Our take: region 4549 can still fire off flares, so keep an eye on the Kp index on clear nights.
Space weather · G3 geomagnetic storm · 10 October 2026
What happened? A solar eruption hit Earth on 10 October
On Thursday 8 October at 15:48 UTC, sunspot region 4549 fired off an M6.7 solar flare, the strongest of the week. The flash briefly knocked out shortwave radio over the Atlantic off Brazil (an R2 radio blackout) and launched a coronal mass ejection: a billion-tonne cloud of magnetised plasma, first estimated at about 900 km/s.
The cloud reached Earth on Saturday 10 October at 14:34 UTC. Forty minutes later, at 15:16 UTC, the magnetometer at Niemegk in Germany recorded a sudden jolt of 56 nanotesla in Earth’s magnetic field. At 17:58 UTC NOAA’s Space Weather Prediction Center reported a strong G3 storm (Kp 7) and kept a G3 warning in force until midnight UTC.
Where were the northern lights seen?
Across the United Kingdom, from Scotland down to England’s south coast, people photographed red and green skies on Saturday evening. In Germany the lights showed up in the north and on webcams in the Sauerland and in Bavaria. Austria was mostly under cloud. We found no confirmed sighting from Türkiye or Greece. From there the aurora has only been seen in strong storms, low in the north and mostly by camera: in November 2023 (G3), May 2024 (G5) and October 2024 (G4). Storm strength alone is not enough; timing, the cloud’s magnetic direction and clear skies decide.
Earlier in the week a weaker cloud from 6 October (from M1.4 and M1.9 flares in the same region) only grazed Earth on 9 October: Kp reached 4 and the forecast G2 storm never came. Space weather forecasts are honest guesses until the cloud arrives, because the direction of its magnetic field is only measured about an hour before impact.
FlareM6.7 · 8 Oct, 15:48 UTC
SourceSunspot region 4549
CME arrival10 Oct, 14:34 UTC
PeakG3 (Kp 7) · from 17:58 UTC
AuroraUK to the south coast, northern Germany
NextG2 watch for 11 Oct
From the Sun to the aurora: how the storm works
Original Astrometrik animation, not to scale. A cloud of solar plasma (orange) leaves the Sun and hits Earth’s magnetic field (teal lines). Energy is funnelled to the poles, where the aurora ovals light up green and red. The bar shows the Kp index rising as the cloud arrives.
What can a G3 storm do?
On NOAA’s five-step scale, G3 is “strong”. Power grids may need voltage corrections, satellites can drift because the upper atmosphere swells and drags on them, GPS and shortwave radio can be patchy, and the aurora can be seen far from the poles. For most people the only effect is the sky show; no serious damage was reported from this storm.
Why are the lights green and red?
The colours come from oxygen and nitrogen high above us. Oxygen at about 100–250 km glows green; above about 250 km, where the air is very thin, it glows deep red. Red is what people far from the poles often see low on the northern horizon, and phone cameras pick it up better than the eye.
How to watch the next one
Look north after dark, away from city lights, between about 22:00 and 02:00. Watch the Kp index: at Kp 5 the aurora can reach Scotland and Scandinavia, at Kp 7 northern Germany and the south of England, and only at Kp 8–9 central and southern Europe. Point your phone camera north with a few seconds of exposure: it often sees colour before your eyes do.
Watch: the solar storm in 34 seconds
Our short video shows the flare, the cloud’s two-day journey, the impact and the auroras, with all the numbers on screen.
Slide the Kp index: how far south does the aurora reach?
The green band is the aurora oval for the chosen Kp. Cities inside the band, or a little south of it, can see the lights low in the north on a clear, dark night.
On 10 October the storm reached Kp 7.
Follow the solar wind live
Astrometrik’s space weather page shows the Kp index, the solar wind and where the aurora oval is right now, updated every hour.
Yes. A coronal mass ejection from the M6.7 flare of 8 October reached Earth at 14:34 UTC on 10 October, and NOAA reported a strong G3 geomagnetic storm (Kp 7) from 17:58 UTC.
Where could the northern lights be seen?
They were photographed across the UK down to England’s south coast and in northern Germany. Austria was mostly cloudy, and we found no confirmed sighting from Türkiye.
Is a G3 geomagnetic storm dangerous?
Not for people on the ground. It can disturb power grids, satellites, GPS and shortwave radio; no serious damage was reported this time.
Will there be more auroras?
NOAA kept a G2 watch for 11 October. Region 4549 can still produce flares, so check the Kp index and the solar wind on the space weather page.
Sources and calculation
Sources: NOAA Space Weather Prediction Center alerts of 10 October 2026 (G2 and G3 warnings, sudden impulse at Niemegk); SpaceWeatherLive (6 Oct CME); EarthSky and The Watchers (flares of 8–10 Oct, region 4549); Met Office and press reports of UK sightings; UBIMET via oe24 (Germany, Austria); earlier sightings in Türkiye: Turkish Space Agency statements via CNN Türk (November 2023) and Posta (October 2024). Text and animations are Astrometrik’s own.
Positions and times were recalculated with Astronomy Engine, the sky-calculation library Astrometrik uses; times for Vienna and Istanbul are local time. The artwork on this page was drawn by Astrometrik.