High-energy solar protons briefly reached S1 – Minor solar radiation storm levels on May 26, 2026, following a large partial halo coronal mass ejection (CME) from the far side of the Sun. The eruption was first detected by the GOES-19 CCOR-1 coronagraph at 22:00 UTC on May 25. Forecast calls for a 10% chance of another S1 or stronger solar radiation storm on May 27.
Proton flux rose sharply following X1.2 solar flare at 07:19 UTC on November 10, 2025, reaching S1 – Minor Solar Radiation Storm levels at 11:20 UTC.
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.
Minor solar radiation storm conditions were registered on March 31, 2025, after an X1.1 solar flare erupted from the Sun’s east limb on March 28.
Early on Sunday, September 8, 2024 (UTC), a magnetic filament erupted from the Sun’s northwest quadrant (N16W22), releasing an Earth-directed coronal mass ejection (CME). The CME is expected to impact Earth on September 10, potentially triggering a G2 – Moderate geomagnetic storm. Concurrently, heightened activity near the Sun’s west limb has caused a sharp increase in proton levels, resulting in an S1 – Minor solar radiation storm at 08:50 UTC today.
A major solar flare measuring X14 erupted on the Sun’s far side at 00:00 UTC on July 23, 2024, producing a full halo coronal mass ejection (CME). The event sent energetic particles throughout the solar system, including Earth, where it caused an S1 – Minor solar radiation storm.
An S1 – Minor solar radiation storm has been in progress since 02:50 UTC on July 23, 2024, and is expected to continue through the rest of the day and possibly into July 24.
Although solar activity was at low levels over the past 24 hours, multiple long-duration C-class solar flares, associated with activity from Region 3599 as it rotated beyond the west limb, produced coronal mass ejections (CMEs) that sent proton flux rising to S1 – Minor levels.
Proton flux started rapidly rising at 07:30 UTC on February 12, 2024, following what appears to be an eruption from the old Region 3575 – now traversing the farside of the Sun.
A moderately strong solar flare measuring M6.7 erupted from Active Region 3559 (beta-gamma) at 04:38 UTC on January 29, 2024. The event started at 03:54 and ended at 05:15 UTC.
