A G3 – Strong geomagnetic storm developed late on March 20 into early March 21, 2026, after a coronal mass ejection that left the Sun on March 18 impacted Earth. The storm intensified after at least two CME arrivals, with solar wind speeds reaching 567 km/s and the interplanetary magnetic field turning strongly southward to −28 nT.
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.
A G3 (Strong) geomagnetic storm is in progress on October 2, 2025, driven by a positive-polarity coronal hole high-speed stream (CH HSS). The U.S. Space Weather Prediction Center (SWPC) issued an active warning valid until 12:00 UTC, with aurora sightings possible as far south as Pennsylvania, Iowa, and Oregon.
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.
At least two coronal mass ejections (CMEs) are heading toward Earth, with impacts expected on December 31 and January 1, 2025. The first CME — much stronger, was produced by a filament eruption associated with an M2.0 flare at 04:30 UTC on December 29 from Active Region (AR) 3939. This resulted in an asymmetric, partial-halo CME first seen in NASA coronagraph imagery at approximately 06:24 UTC.
The coronal mass ejection (CME) produced by the X9.0 solar flare on October 3, 2024, impacted Earth around 07:30 UTC on October 6, elevating solar wind parameters.
Coronal mass ejection (CME) produced by a filament eruption early Sunday, September 8, 2024, hit Earth at around 03:50 UTC on September 12. The impact sparked G3 – Strong geomagnetic storming and widespread red aurora.
The coronal mass ejection (CME) produced by the X1.3 solar flare on August 14, 2024, impacted Earth around 14:30 UTC on August 18, producing G3 – Strong geomagnetic storming.
A G3 – Strong geomagnetic storming was observed on August 12, 2024, following multiple impacts from coronal mass ejections (CMEs) produced since August 7.
A coronal mass ejection (CME) produced by a long-duration M8.2 solar flare at 07:09 UTC on August 1, 2024, reached Earth early on August 4, causing G3 – Strong geomagnetic storming.
