Moderate M1.0 solar flare erupts at 05:27 UTC on October 20, 2025

A moderate M1.0 solar flare erupted at 05:27 UTC on October 20, 2025.

Today’s flares include a minor C5.9 flare that peaked at 02:34 UTC on October 20, 2025 from active region 4246. No X-class or other M-class solar flares are listed on this day in available edited events data.

In 24 hours to 00:30 UTC on October 20, solar activity reached moderate levels. Most of the period’s flare activity originated from region 4246, including M- and C-class flares, with new regions 4259 and 4260 numbered and no Earth-directed CMEs detected in available imagery.

Solar activity is expected to remain low, with a decreasing chance for isolated M-class flares in the period October 20 to 22.

Active sunspot regions presently observed on the Earth-facing solar disk include AR 4246 (N25W00 – Beta), AR 4248 (N06W81 – Beta), AR 4252 (S13W28 – Beta), AR 4254 (N10E06 – Alpha), AR 4256 (S15E26 – Beta), AR 4257 (S10E48 – Beta), AR 4258 (S14W55 – Alpha), AR 4259 (S20E49 – Beta), and AR 4260 (S10E61 – Alpha).

Over the past 24 hours, the greater than 2 MeV electron flux was at normal to moderate levels, while the greater than 10 MeV proton flux remained at background levels. The electron flux is expected to increase to high levels during October 20 to 22, with proton flux remaining at background values through October 21.

Solar wind parameters were enhanced during the period due to CME influences, followed by onset of negative polarity coronal hole high speed stream influences early in the period. The total magnetic field strength reached 12 nT, with the Bz component mainly sustained southward by as much as -8 nT late in the period. Solar wind speeds ranged between about 455 and 575 km/s with a variable phi angle. Enhanced solar wind conditions and influences from the negative polarity coronal hole high speed stream are expected to prevail through October 22.

The geomagnetic field reached G1 – Minor storm levels in the past 24 hours due to CME and negative polarity coronal hole high speed stream influences. Periods of active conditions are likely over October 19 to 20 due to these influences, with quiet to unsettled conditions expected to prevail on October 21 and 22 as these effects wane.