Viewing archive of Sunday, 28 June 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Jun 28 1231 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
28 Jun 2026	160	007
29 Jun 2026	160	007
30 Jun 2026	158	016

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. The largest flare was a C7.4 flare (SIDC Flare 8035) peaking on June 27 at 21:02 UTC, which was produced by SIDC Sunspot Group 899 (NOAA Active Region 4475). A total of 6 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 886 (NOAA Active Region 4478) (Beta-gamma-delta) and SIDC Sunspot Group 899 (NOAA Active Region 4475) (beta gamma) are the most complex active regions and in charge of the majority of the C-class flaring of the past 24 hours. Solar flaring activity is expected to be moderate over the next 24 hours, with C-class flares expected and a M-class flares very likely.

Coronal mass ejections

The CME that was first seen in LASCO C2 from 21:15 UTC June 26 is mainly directed towards the south but still has a Earth directed component. The arrival of the associated ICME is expected for June 30.

Coronal holes

A large mid-latitude to equatorial positive polarity coronal hole started crossing central meridian with the mid-latitude extension, and may enhance solar wind conditions around July 1.

Solar wind

Solar wind conditions near Earth have returned to slow solar wind, with speeds around 450 km/s, magnetic field around 3nT and the minimum Bz reaching -2nT. Slow solar wind conditions are expected for the next 24h.

Geomagnetism

Geomagnetic conditions were quite globally (Kp 2) and quite to unsettled locally (Kbel 3) over the past 24 hours. Quiet to unsettled conditions are expected for the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux, as measured by GOES-18, was below the 10 pfu threshold level over the past 24 hours and is expected to remain so for the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux was above the 1000 pfu alert threshold for the last 24 hours, and is expected to remain above the threshold during the next 24 hours. The 24h electron fluence was at moderate levels and is expected to remain so for the next 24 hours.

Today's estimated international sunspot number (ISN): 150, based on 19 stations.

Solar indices for 27 Jun 2026

Wolf number Catania	///
10cm solar flux	188
AK Chambon La Forêt	010
AK Wingst	009
Estimated Ap	008
Estimated international sunspot number	127 - Based on 24 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

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