A long-duration solar flare measuring M7.1 at its peak erupted from Active Region 4324 at 13:51 UTC on December 31, 2025. The event started at 13:12 and ended at 14:11 UTC.
A coronal mass ejection (CME) associated with an M4.2 solar flare from Region 4317 is expected to produce a G1 – Minor geomagnetic storm as it grazes Earth late on December 31 into early January 1, 2026.
Auroras are expected across much of the northern United States, southern Canada, and northern Europe on December 9, 2025, following a forecasted geomagnetic disturbance caused by a coronal mass ejection (CME) produced during the December 6 M8.1 solar flare.
A major solar flare measuring X1.1 erupted from Active Region 4298 at 05:01 UTC on December 8, 2025. The event started at 04:49 and ended at 05:04 UTC.
A G3 – Strong geomagnetic storm watch is in effect following a powerful M8.1 solar flare from geoeffective Active Region 4299 at 20:39 UTC on December 6, 2025. The resulting full-halo coronal mass ejection (CME) is expected to impact Earth between early and midday UTC on December 9, possibly producing periods of strong geomagnetic storming.
A strong solar flare measuring M8.1 erupted from Active Region 4299 at 20:39 UTC on December 6, 2025. The event started at 20:29 and ended at 20:49 UTC. A full-halo coronal mass ejection was produced, with impact expected early to midday on December 9, potentially causing periods of G3 – Strong geomagnetic storming.
A strong M6.0 solar flare erupted from Region 4300 at 02:50 UTC on December 4, 2025, producing a non-Earth-directed CME. The flare occurred as Earth’s geomagnetic field remained in storm conditions, including a G3 – Strong interval driven by the arrival of a negative CH HSS and the flank of the CME launched on December 1. Solar wind parameters showed elevated density, strong IMF values, and Bz reaching −15 nT before transitioning to high-speed stream conditions.
NOAA’s Space Weather Prediction Center (SWPC) issued a G2 – Moderate geomagnetic storm watch for December 3 and 4, 2025, following a coronal mass ejection (CME) associated with the X1.9 solar flare from Active Region 4299 on December 1. The CME is expected to deliver a glancing blow to Earth’s magnetic field, coinciding with a co-rotating interaction region (CIR) and a sector boundary crossing, increasing the potential for moderate geomagnetic storming and visible auroras at mid-latitudes.
A major solar flare registered as X1.9 erupted from Active Region 4299 at 02:49 UTC on December 1, 2025. The event started at 02:27 and ended at 03:05 UTC. This region is currently making its second run through the Earth-side of the Sun, after producing multiple X-class flares in early November.
UK researchers report that radiation levels at commercial flight altitudes reached their highest values in 20 years following the X5-class solar flare on November 11, 2025, with the resulting Ground Level Enhancement driving single-event upset rates in avionics not seen since 2006.
