C7.9 solar flare erupts on June 15, 2025

A minor C7.9 solar flare erupted at 19:31 UTC on June 15, 2025.

Today’s flares include an M8.4 flare from region 4114 which peaked at 18:07 UTC, an M2.2 flare from region 4105 that peaked at 07:56 UTC, and an M1.9 flare from region 4105 that peaked at 10:47 UTC. Several C-class flares were also recorded.

In 24 hours to 12:30 UTC on June 15, solar activity reached R1-R2 (minor to moderate) levels, with multiple minor flares and a moderate flare. No additional CMEs were observed in this period.

Solar activity is likely to be moderate, with a chance for R1-R2 (minor to moderate) events and a slight chance for R3 (strong) flares through June 17.

There are currently 7 numbered active regions on the Earth-facing side of the Sun: AR 4105 (S15W71, Beta), AR 4107 (S15W93, Beta), AR 4110 (N06W58, Beta), AR 4111 (N14W00, Alpha), AR 4113 (N10E18, Alpha), AR 4114 (N17E26, Beta-Gamma), AR 4115 (N21E40, Beta), and AR 4116 (S12E26, Beta).

Over the past 24 hours, greater than 2 MeV electron flux was at normal to moderate levels, while greater than 10 MeV proton flux remained at background levels. The greater than 2 MeV electron flux is expected to be at moderate to high levels on June 15–17, with a slight chance for an S1 – Minor solar radiation storm.

Solar wind parameters indicated a transition to a positive polarity coronal hole high speed stream, with speed increasing from about 430 km/s to between 480–535 km/s and the total field near 7 nT. These conditions are expected to persist through June 17, with varying speeds and a possible increase later on June 16.

The geomagnetic field was at quiet to unsettled levels due to coronal hole high speed stream effects. HSS activity is expected to result in unsettled to active intervals from June 15–17, with likely periods of G1 – Minor geomagnetic storm on June 15 and June 16.