Strong M8.1 solar flare erupts at 20:39 UTC on December 6, 2025

A strong M8.1 solar flare erupted at 20:39 UTC on December 6, 2025.

Today’s flares include a C6.4 event from region 4294 peaking at 03:09 UTC, a C5.7 flare from region 4297 at 01:23 UTC, a C3.6 flare from region 4298 at 09:45 UTC, and multiple C-class flares from regions 4294 and 4299. No M-class or X-class flares are recorded in the available event listings as of 20:52 UTC.

In 24 hours to 12:30 UTC on December 6, solar activity was at low levels, with the largest event being a C6.4 flare at 03:09 UTC.

M-class flares are likely over December 6–8, with a slight chance for X-class flares according to current active region potential and recent flare history.

Active sunspot regions presently observed on the Earth-facing solar disk include AR 4294 (S15W09 – Beta-Gamma-Delta), AR 4295 (N04W03 – Beta), AR 4296 (S14E10 – Beta), AR 4298 (S18W24 – Beta), AR 4299 (N21E15 – Beta-Delta), AR 4300 (N08E25 – Beta), and AR 4301 (S09W72 – Beta).

Over the past 24 hours, the greater than 2 MeV electron flux in geosynchronous orbit reached high levels, with a peak flux of 1 430 pfu. The greater than 10 MeV proton flux remained at background levels. The greater than 2 MeV electron flux is expected to continue at high levels over December 6–8, with a slight chance of greater than 10 MeV proton flux reaching S1 – Minor storm level due to the activity of multiple regions.

Solar wind conditions reflected the ongoing influence of a negative polarity coronal hole high-speed stream. Total magnetic field strength ranged from 4–8 nT, with the Bz component reaching as far south as -6 nT and wind speeds fluctuating between approximately 600–700 km/s. The solar wind environment is expected to remain enhanced by this negative polarity coronal hole high-speed stream for December 6–7, with an additional enhancement likely late on December 7 and into December 8 due to glancing effects from a CME that left the Sun on December 4.

Geomagnetic activity was at quiet to active levels during the past day as a result of the negative polarity coronal hole influence. Geomagnetic conditions are likely to reach active levels on December 6 as coronal hole effects wane. G1 – Minor geomagnetic storm conditions are likely on December 7–8 due to the anticipated arrival of a CME that departed the Sun on December 4.