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Solar activity report
Report of Solar-Geophysical Activity 2025 Sep 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 264 Issued at 2200Z on 21 Sep 2025IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity has been at low levels for the past 24 hours.
There are currently 10 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (22 Sep, 23 Sep,
24 Sep).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 354 km/s at 21/0844Z. Total IMF reached 7 nT at
21/2021Z. The maximum southward component of Bz reached -4 nT at
21/1304Z. Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 4819 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (22 Sep), quiet to
unsettled levels on day two (23 Sep) and quiet levels on day three (24
Sep).
III. Event Probabilities 22 Sep to 24 Sep
| Class M | 40% | 40% | 40% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Sep 176 Predicted 22 Sep-24 Sep 180/180/185 90 Day Mean 21 Sep 146
V. Geomagnetic A Indices
Observed Afr/Ap 20 Sep 005/005 Estimated Afr/Ap 21 Sep 008/010 Predicted Afr/Ap 22 Sep-24 Sep 019/024-009/012-005/005
VI. Geomagnetic Activity Probabilities 22 Sep to 24 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 40% | 20% | 10% |
| Minor storm | 25% | 05% | 01% |
| Major-severe storm | 05% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 15% | 15% |
| Minor storm | 25% | 25% | 20% |
| Major-severe storm | 60% | 25% | 20% |
All times in UTC
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Space weather facts
| Last X-flare | 2026/01/18 | X1.9 |
| Last M-flare | 2026/01/21 | M3.4 |
| Last geomagnetic storm | 2026/01/22 | Kp5+ (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| December 2025 | 124 +32.2 |
| January 2026 | 118.7 -5.3 |
| Last 30 days | 120.4 +5.6 |