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.
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.
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.
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.
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.
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.
A G5 – Extreme geomagnetic storm in May 2024 revealed just how far-reaching space weather can be. From subtle shifts in Earth’s upper atmosphere to radiation spikes on Mars, the event challenged infrastructure, disrupted systems, and gave scientists an enormous archive of data.
Four solar filament eruptions between May 6 and 7, 2025, produced fast-moving CMEs, all of which are expected to pass north or south of the Earth without impacting us. G1 – Minor storm conditions are likely on May 9 due to a combination of CH HSS and a possible glancing blow from a CME launched on May 5.
Solar activity increased on April 29, 2025, with three M-class solar flares recorded during the first half of the UTC day as large Active Region 4079 rotated into Earth’s view. Region 4079, formerly designated AR 4055, underwent significant growth while on the far side of the Sun and is expected to be the primary source of solar activity in the coming days.
A coronal mass ejection produced by a filament eruption on April 13 impacted Earth’s magnetic field at 16:37 UTC on April 15, sparking a G2 – Moderate geomagnetic storm. A G3 – Strong geomagnetic storm watch is in effect for April 16 due to the anticipated arrival of additional CMEs.
