C9.8 solar flare erupts on June 15, 2025

A moderate C9.8 solar flare erupted at 19:50 UTC on June 15, 2025.

Today’s flares include an M8.4 flare from region 4114 peaking at 18:07 UTC, an M2.2 from region 4105 at 07:56 UTC, and an M1.9 from region 4105 at 10:47 UTC. Numerous C-class flares were also observed from regions 4114, 4111, and 4110 throughout the day.

In 24 hours to 12:30 UTC on June 15, solar activity was at R1 – Minor to R2 – Moderate levels. There were numerous R1 events and one R2 event, with regions 4105 and 4114 showing the most growth and flare activity.

Solar activity is likely to remain at moderate (R1-R2, Minor-Moderate) levels with a slight chance for R3 – Strong (X-class) flares through June 17.

There are currently 7 numbered active regions on the Earth-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 and greater than 10 MeV proton flux was at background levels. Electron flux is expected to be at moderate to high levels through June 17, with a slight chance for an S1 – Minor proton event.

Over the past day, solar wind parameters indicated a transition to a positive polarity coronal hole high speed stream, with speeds increasing from around 430 km/s to between 480-535 km/s. HSS conditions are anticipated to persist through June 17, with variations in solar wind speed and a possible increase on June 16.

The geomagnetic field was at quiet to unsettled levels due to coronal hole high speed stream effects. Unsettled to active periods are likely on June 15-17, with G1 – Minor geomagnetic storm periods expected on June 15-16.