Strong M8.4 solar flare erupts from AR 4114, CME produced
A strong M8.4 solar flare erupted from Active Region 4114 at 18:07 UTC on June 15, 2025. This event began at 17:45 UTC, peaked at 18:07 UTC, and ended at 18:25 UTC.
CH HSS sparks G2 – Moderate geomagnetic storm
Elevated geomagnetic activity was recorded on Earth on June 13, 2025, due to the waning effects of a negative polarity coronal hole high-speed stream and possible transient effects.
S1 – Minor solar radiation storm in progress following M8.1 solar flare
An S1 – Minor solar radiation storm began at 17:00 UTC on May 31, 2025. The storm is linked to a long-duration M8.1 solar flare from Active Region 4100 at 00:05 UTC on May 31. Minor HF radio signal fades are being reported at high latitudes.
G4 – Severe geomagnetic storm watch issued for June 2 following strong Earth-directed CME
The U.S. Space Weather Prediction Center (SWPC) issued a G4 – Severe geomagnetic storm watch for June 2, 2025, following the eruption of a powerful, Earth-directed coronal mass ejection (CME) associated with a long-duration M8.1 solar flare from Active Region 4100. The CME is forecast to arrive at Earth late on June 1, with geomagnetic storm conditions expected to intensify through June 2.
Long-duration M8.1 solar flare produces strong Earth-directed CME, impact expected on June 1
A strong, long-duration solar flare registered as M8.1 erupted from Active Region 4100 at 00:05 UTC on May 31, 2025. The flare began at 23:31 UTC on May 30 and ended at 01:32 UTC on May 31. The eruption produced a significant coronal mass ejection (CME). Model forecasts indicate that the CME is Earth-directed and is expected to arrive on June 1.
M3.4 solar flare erupts from AR 4100, Earth-directed CMEs possible in coming days
A moderately strong solar flare measuring M3.4 erupted from Active Region 4100 at 06:13 UTC on May 30, 2025. The event started at 05:40 and ended at 06:19 UTC. A coronal mass ejection (CME) may have been produced during the event, and there is a possibility that part of it is directed toward Earth.
Negative polarity CH HSS triggers G3 – Strong geomagnetic storm
A G3 – Strong geomagnetic storm was observed at 02:16 UTC on May 29, 2025, triggered by the arrival of a negative polarity coronal hole high-speed stream at Earth. Coronal hole high-speed streams, and their associated transition zones called co-rotating interaction regions (CIRs), can create CME-like shock waves that are capable of producing strong geomagnetic disturbances and widespread auroras.
Major X1.1 solar flare erupts from Region 4098
A major solar flare measuring X1.1 erupted at 01:52 UTC on May 25, 2025, from Active Region 4098 located in the southwest quadrant. The event began at 01:46 UTC and ended at 01:57 UTC. Multiple associated radio bursts were detected between 01:48 and 01:53 UTC.
Major X2.7 solar flare erupts from Active Region 4087
A major solar flare measuring X2.7 erupted from Active Region 4087 at 08:19 UTC on May 14, 2025. The event began at 08:04 and ended at 08:31 UTC. This is the 8th X-class solar flare of the year and the strongest to date. It currently ranks as the 15th most powerful flare of Solar Cycle 25, exceeding the X2.56 event observed on February 16, 2024. This is also the second X-class flare within the past 24 hours, following an X1.2 flare at 15:38 UTC on May 14 from a region near the Sun’s west limb.
Major X1.2 solar flare erupts from Sun’s west limb
A major solar flare measuring X1.2 erupted from Active Region 4086 at 15:38 UTC on May 13, 2025. The event started at 15:25 and ended at 15:44 UTC. This is the seventh X-class solar flare of the year and the first since March 28, tying for the third strongest with the X1.2 flare on January 3.
