Moderate M1.8 solar flare erupts at 06:40 UTC on August 25, 2026

A moderate M1.8 solar flare erupted at 06:40 UTC on August 25, 2026.

Today’s flares include an M1.9 flare that began at 01:04 UTC, peaked at 01:26 UTC, and ended at 01:40 UTC from region 4513; a C4.9 flare that began at 03:35 UTC, peaked at 03:47 UTC, and ended at 03:55 UTC from region 4513; an M1.0 flare that began at 03:55 UTC, peaked at 04:02 UTC, and ended at 04:07 UTC from region 4513; and a C1.6 flare that began at 05:48 UTC, peaked at 05:55 UTC, and ended at 06:00 UTC. All reported flares were observed on August 25, 2026.

In 24 hours to 00:30 UTC on August 25, solar activity reached moderate levels due to an M1.7 flare. Slight growth and separation were noted in region 4513, with slight growth also in regions 4516 and 4517, while region 4515 remained stable.

Solar activity is expected to be at low levels, with a chance for M-flares (R1 – Minor to R2 – Moderate radio blackouts) and a slight chance for an X-flare (R3 – Strong or greater) during August 25–27.

Active sunspot regions presently observed on the Earth-facing solar disk include AR 4513 (N04E10 – Beta-Gamma-Delta), AR 4515 (S08E23 – Alpha), AR 4516 (N17W55 – Beta), and AR 4517 (N10W03 – Beta).

Over the past 24 hours, the greater than 2 MeV electron flux reached high levels, with a peak flux of 1 640 pfu. The greater than 10 MeV proton flux remained elevated but below S1 – Minor levels, ranging from 2–4 pfu through the period. There is a chance for the greater than 10 MeV proton flux to reach S1 – Minor solar radiation storm levels on August 25 due to previous activity, with a decrease in likelihood expected for August 26–27.

Solar wind parameters remained at nominal levels, with average wind speeds near 365 km/s, total field between 4–6 nT, and the Bz component varying between ±4 nT. Nominal solar wind conditions are expected until midday August 27, followed by a likely enhancement from mid to late August 27 as a positive polarity coronal hole high speed stream becomes geoeffective, bringing wind speeds in the 500–600 km/s range.

The geomagnetic field was quiet to unsettled under ambient solar wind conditions. Mostly quiet geomagnetic conditions are expected through midday August 27. Unsettled to active levels are likely from late August 27 onward, with a chance for G1 – Minor geomagnetic storm levels due to enhanced solar wind associated with a coronal hole high speed stream.