Viewing archive of Friday, 18 July 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Jul 18 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
18 Jul 2025	154	011
19 Jul 2025	150	012
20 Jul 2025	145	007

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with six C-class flares identified. SIDC Sunspot Group 522 (NOAA Active Region [AR] 4136, Beta-Delta magnetic configuration) produced most of these flares, including the brightest (SIDC flare 4909, C3 magnitude, on 18 Jul at 08:13 UTC). A flare were produced by each of SIDC Sunspot Group 522 (NOAA AR 4136, Beta-Delta magnetic configuration) and SIDC Sunspot Group 558 (NOAA AR 4142, Beta-Gamma magnetic configuration). More C-class flaring activity is expected in the next 24 hours.

Coronal mass ejections

No Earth-directed Coronal Mass Ejections (CME) were observed in the last 24 hours.

Solar wind

During the past 24 hours the Solar Wind (SW) conditions continued to be affected by the the High Speed Stream (HSS) that arrived on 11 July and is associated with SIDC Coronal Hole 104 (positive polarity). The SW speed initially peaked at 790 km/s on 17 Jul at 15:00 UTC but has significantly subsided since and is now around 550 km/s.The interplanetary magnetic field (B) varied between 3 and 8 nT and its North-South component (Bz) fluctuated between -7 and 6 nT. The fast SW conditions are expected wane in the next 24 hours.

Geomagnetism

During the past 24 hours the geomagnetic conditions were globally active (NOAA Kp 4-) with short unsettled to quiet (NOAA Kp 1 to 3) intervals. Locally the conditions were quiet to active (K BEL 2 to 4) for the same period of time. The conditions are expected to become quiet to unsettled in the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux, as measured by the GOES-19 satellite, was at background levels over the past 24 hours and is expected to remain so in the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by GOES 19, was above the 1000 pfu alert threshold during the past 24 hours. It is expected to remain above the threshold level in the next 24 hours. The 24-hour electron fluence was at moderate levels during the past 24 hours and is expected to remain at the current levels in the next 24 hours.

Today's estimated international sunspot number (ISN): 177, based on 18 stations.

Solar indices for 17 Jul 2025

Wolf number Catania	///
10cm solar flux	156
AK Chambon La Forêt	025
AK Wingst	023
Estimated Ap	023
Estimated international sunspot number	196 - Based on 28 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page