Viewing archive of Saturday, 31 January 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Jan 31 1232 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
31 Jan 2026	130	005
01 Feb 2026	134	005
02 Feb 2026	137	005

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. A total of 11 numbered sunspot groups were identified on the visible solar disk over the past 24 hours. Most regions have been magnetically simple (classified as magnetic type alpha or beta), except for SIDC Sunspot Group 784 (NOAA Active Region 4366), which has exhibited significant growth and increased the complexity of its underlying magnetic field configuration. The region was responsible for most of flaring activity over the period and is currently classified as magnetic type beta-gamma-delta. The largest recorded flare was a C6.0 flare (SIDC Flare 6772) with peak time 05:12 UTC on Jan 31 attributed to activity from SIDC Sunspot Group 769 (NOAA Active Region 4349) near the west limb. The solar flaring activity is expected to be low over the next 24 hours with very likely C-class flares and increasing probability for M-class flaring.

Coronal mass ejections

No Earth-directed coronal mass ejections (CMEs) have been identified in the available coronagraph imagery over the past 24 hours.

Solar wind

Over the past 24 hours the solar wind parameters (as measured by ACE at L1) exhibited a gradual decrease towards nominal slow solar wind conditions. The solar wind speed gradually decreased to 414 km/s. The interplanetary magnetic field (B) was weak a maximum magnitude below 4.5 nT and a minimum north-south (Bz) component of - 3.4 nT. The B field phi angle remained predominantly in the negative sector (directed towards the Sun) reflecting the polarity of the previously geo-effective coronal hole (SIDC Coronal Hole 147). The solar wind parameters are expected to reflect nominal slow solar wind conditions over the next days.

Geomagnetism

The geomagnetic conditions over the past 24 hours have been globally quiet. Quiet to unsettled conditions were observed locally over Belgium. Predominantly quiet geomagnetic conditions are expected for the next days with possible isolated unsettled periods.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux was at nominal levels and it is expected to remain so over the 24 hours. Some enhancements are possible in case of strong eruptive activity particularly related to SIDC Sunspot Group 784 (NOAA Active Region 4366).

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux as measured by GOES 18 and GOES 19 was continuously exceeding the 1000 pfu threshold over the past 24 hours. The greater than 2 MeV electron flux is expected to remain above the 1000 pfu threshold for prolonged periods of time over the next days. The 24-hour electron fluence was at the border of moderate to high levels and is expected to remain so over the 24 hours.

Today's estimated international sunspot number (ISN): 118, based on 09 stations.

Solar indices for 30 Jan 2026

Wolf number Catania	///
10cm solar flux	128
AK Chambon La Forêt	///
AK Wingst	009
Estimated Ap	010
Estimated international sunspot number	094 - Based on 15 stations

Noticeable events summary

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

All times in UTC

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