Viewing archive of Saturday, 23 August 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Aug 23 1231 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
23 Aug 2025	125	008
24 Aug 2025	126	007
25 Aug 2025	128	007

Solar Active Regions and flaring

Solar flaring activity was moderate over the past 24 hours, with 1 M-class flare identified. A total of 6 numbered sunspot groups were identified on the disk over the past 24 hours, all having alpha or beta magnetic configuration. The largest flare was a M1.7 flare (SIDC Flare 5188) peaking on August 22 at 18:51 UTC from a region behind the east-limb. Solar flaring activity is expected to be low over the next 24 hours, with C-class flares very likely and a chance for M-class flares.

Coronal mass ejections

A halo Coronal Mass Ejection (CME) was detected in SOHO/LASCO-C3 data from 17:12 UTC Aug 22, and will be further analysed when more data become available. A partial halo CME reported by CACTus as launched on 22 Aug at 05:24 UTC is the combination of two CME which are not expected to become geo-effective.

Coronal holes

The SIDC Coronal Hole 126 (mid-latitude coronal hole with a negative polarity) is crossing the central meridian. A high-speed stream from this coronal hole may enhance the solar wind environment near Earth on August 26.

Solar wind

Slow solar wind conditions were recorded over the past 24 hours, with speed around 460 km/s. The interplanetary magnetic field was around 4 nT, with the Bz reaching a minimum value of -2 nT. Slow solar wind conditions are expected in the next 24 hours.

Geomagnetism

Geomagnetic conditions were globally and locally quiet to unsettled (Kp 3 and K Bel 3). Quiet conditions are expected in the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux remained below the 10 pfu threshold and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

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

Today's estimated international sunspot number (ISN): 071, based on 10 stations.

Solar indices for 22 Aug 2025

Wolf number Catania	050
10cm solar flux	136
AK Chambon La Forêt	013
AK Wingst	010
Estimated Ap	010
Estimated international sunspot number	056 - Based on 21 stations

Noticeable events summary

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

All times in UTC

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