Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 23, 2026 at 06:50 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data since 2003.01 (January 1, 2026)
Solar cycle Solar cycles 23-25 (January 1, 2026) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (January 1, 2026) Noon SDO sunspot count 1K image / 4K (*)
  Solar cycles 1-24 (August 1, 2020) POES auroral activity level [October 2009 - December 2012]
  Comparison of cycles 21-25 (January 1, 2026) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (January 1, 2026) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (December 21, 2025) Cycle 25 initial spots (final update December 25, 2019)
  Solar cycles 24-25 transition using 365d smoothing  

Recent activity

The geomagnetic field was at quiet to minor storm levels on January 22, predominantly under the influence of effects from CH1340. Solar wind speed at SOHO ranged between 463 and 675 km/sec, averaging 570 km/sec (-153 km/sec compared to the previous day). The high latitude magnetometer at Andenes was at unsettled to major storm levels. The above 10 MeV proton flux decreased gradually and was near 4 pfu at the end of the UT day.

Solar flux density measured at 20h UT on 2.8 GHz was 194.4 - increasing 28.0 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 151.71 (183 days ago). The 81 day average solar flux at 1 AU was 146.9 (41 days ago, this is 49.2% of the total SC25 solar flux range from the max 81 day average peak on September 4, 2024 at 227.3 and an average 81 day flux of 69 at solar minimum). SC25 365d peak: 195.9 on October 13, 2024.

The Potsdam WDC planetary A index was 16 (STAR Ap - based on the average of three hour interval ap indices: 16.0). Three hour interval K indices: 43222225 (planetary), 43222315 (Boulder), 54333336 (Andenes).

The background x-ray flux is at the class C1 level (GOES 19).

At the time of counting spots (see image time), spots were observed in 18 active regions using 2K resolution (SN: 412) and in 15 active regions using 1K resolution (SN: 271) SDO/HMI images.

AR 14341 [S10W33] decayed further and was mostly quiet.
AR 14342 [N17W30] was mostly quiet and stable. Note that SWPC groups AR S11780 with this AR.
AR 14343 [S11W84] decayed slowly and quietly.
AR 14344 [N18W40] was quiet and stable.
AR 14345 [S17W29] decayed slowly and produced a few C flares. C1 flares: C1.7 @ 06:36, C1.8 @ 13:52 UT
AR 14347 [N10W05] was mostly quiet and stable.
AR 14348 [S17W59] decayed slowly and quietly
AR 14349 [S13E34] produced the largest flare of the day. Slow decay was observed.
AR 14350 [N20E18] decayed slowly and quietly.
AR 14351 [S05E07] developed further and was mostly quiet. C1 flares: C1.5 @ 21:57 UT
New AR 14353 [N17E11] emerged quickly on January 21 and developed further the next day when it was numbered by SWPC. M flares are possible. C1 flares: C1.5 @ 00:23, C1.5 @ 00:47, C1.7 @ 02:27, C1.7 @ 09:41, C1.5 @ 18:56, C1.9 @ 19:41, C1.5 @ 22:19, C1.9 @ 22:34, C1.5 @ 22:51 UT
New AR 14354 [S12E14] emerged with several spots.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S11780 [N12W31] decayed significantly and was mostly quiet. C1 flares: C1.6 @ 09:27 UT
AR S11793 [N18E28] was quiet and stable.
AR S11798 [S12E68] has tiny spots spread over a large area.
New AR S11801 [N08E11] emerged with tiny spots.
New AR S11802 [S24W20] emerged with a tiny spot.
New AR S11803 [S22W43] emerged with tiny spots.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.2 01:28   14347 GOES18  
C2.0 03:53   14345 GOES18  
C2.1 04:11   14351 GOES18  
C8.3 10:49   14345 GOES18  
C2.3 12:23   14342 GOES18  
C2.0 15:38   14345 GOES18  
C4.3 17:07   14351 GOES18  
C2.6 17:45   14353 GOES18  
C2.0 18:26   14353 GOES18  
C9.5 19:54   14353 GOES18  
C2.4 20:24   14353 GOES18  
C2.1 20:33   14353 GOES18  
C2.3 21:22   14345 GOES18  
C2.0 23:10   14341 GOES18  
C2.6 23:52   14341 GOES18  

Coronal mass ejections (CMEs)

January 20-22: No obviously Earth directed CMEs were observed in available coronagraph imagery.

Coronal holes

[Coronal hole history (since October 2002)]
[Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago]

A huge recurrent trans equatorial positive polarity coronal hole (CH1340) was Earth facing on January 15-22. A recurrent trans equatorial negative polarity coronal hole (CH1341) will likely rotate across the central meridian on January 24-25.

Forecast

The geomagnetic field is expected to be at quiet to active levels on January 23-25 due to effects associated with CH1340.

Coronal holes (1) Coronal mass ejections (2) M and X class flares (3)
     

1) Effects from a coronal hole could reach Earth within the next 5 days. When the high speed stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.

Green: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% probability.

Active solar regions



(Click on image for 2K resolution). 4K resolution. Compare to the previous day's image.
0.5K image

When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.

Data for all officially numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC, all other regions are numbered sequentially as they emerge using the STAR spot number. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers. SWPC data considered to be not sufficiently precise (location, area, classification) are colored red.

Active region SWPC date numbered
STAR detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlays
Comment
SWPC/
USAF
STAR SWPC STAR Current Previous
2K 1K
14341 2026.01.13
2026.01.14
12 23 12 S11W35 0240 CAI CKO

was AR S11770

area: 0350

location: S10W33

14342 2026.01.14
2026.01.14
13 8 1 N14W31 0180 DSI CSO

was AR S11772

area: 0180

location: N17W30

SWPC includes the spots of AR S11780

14343 2026.01.14
2026.01.15
1 2 1 S11W84 0020 HRX HRX

was AR S11774

area: 0006

14344 2026.01.15 1 6 1 N19W42 0010 AXX AXX

location: N18W40

14345 2026.01.15
2026.01.15
17 33 21 S17W28 0110 EAI ESI beta-gamma

was AR S11776

area: 0270

14346 2026.01.15
2026.01.15
      S14W21           was AR S11777

location: S13W13

S11779 2026.01.15       N12W47            
S11780 2026.01.15   21 8 N12W31 0130   DAO  
14347 2026.01.16
2026.01.16
1 5 1 N10W05 0060 HSX CSO was AR S11781

area: 0120

S11783 2026.01.16       N02W23            
14348 2026.01.18
2026.01.18
4 8 5 S17W59 0010 CRO CRO was AR S11784

area: 0040

14350 2026.01.18
2026.01.19
3 6 3 N21E17 0010 AXX AXX was AR S11786

location: N20E18

14351 2026.01.18
2026.01.19
16 34 18 S05E07 0080 DAI DRI beta-gamma

was AR S11787

area: 0150

S11788 2026.01.18       N04W21            
14349 2026.01.18
2026.01.19
5 25 8 S14E35 0120 CSO CHI was AR S11789

area: 0440

location: S13E34

14352 2026.01.20
2026.01.20
      S02W05         was AR S11790

loction: S01W04

S11791 2026.01.20       S05W02            
S11793 2026.01.20   3 1 N18E28 0005   BXO  
S11794 2026.01.20       S14W16            
14353 2026.01.21
2026.01.22
10 34 21 N17E23 0040 DRI DRI beta-gamma

was AR S11797

area: 0220

S11798 2026.01.21   5 1 S13E68 0020   CRO  
S11799 2026.01.21       N05E23          
14354 2026.01.22
2026.01.22
3 14 8 S13E13 0010 BXO DRI   was AR 11800

area: 0040

location S12E14

S11801 2026.01.22   2 1 N08E11 0005   BXO    
S11802 2026.01.22   1   S24W20 0001   AXX    
S11803 2026.01.22   2   S22W43 0002   BXO    
Total spot count: 86 232 111  
Sunspot number: 206 412 271  (total spot count + 10 * number of spotted regions)
Weighted SN: 127 290 183  (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10)
Relative sunspot number (Wolf number): 227 227 217  

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2024.05 187.7 191.9 172.1 149.1 (+4.6) 23.56
(SC25 peak)
2024.08  246.1
(SC25 peak)
252.2 216.0  (SC25 peak) 156.8 (+1.8) 15.96
2024.10 221.0 219.6 165.8 160.9 (+1.5) (SC25 solar max) 18.99
2024.11 199.6 195.3 154.1 157.2 (-3.7) 9.33
2024.12 197.3 191.2 154.6 151.2 (-6.0) 8.42
2025.01 190.3 184.2 137.0 146.2 (-5.0) 13.17
2025.02  184.2 179.7 155.7 139.8 (-6.4) 14.42
2025.03 163.7 162.1 134.2 135.9 (-3.9) 15.96
2025.04 162.5 163.6 141.4 133.3 (-2.6) 17.62
2025.05  135.3 138.3 78.5 128.6 (-4.7) 17.26
2025.06 131.3 135.4 114.6 124.7 (-3.9) 21.43
2025.07 137.8 142.3 125.9 (122.4 projected, -2.3) 11.80
2025.08 154.9 158.7 133.7 (119.3 projected, -3.1) 9.97
2025.09 154.4 156.0 129.7 (115.8 projected, -3.5) 14.02
2025.10 139.5 138.6 114.6 (111.8 projected, -4.0) 15.64
2025.11 140.3 137.3 91.7 (109.6 projected, -2.2) 21.01
2025.12 160.8 155.8 124.0 (108.0 projected, -1.6) 13.35
2026.01 149.4 (1)   81.3 (2A) / 114.5 (2B) / 141.0 (2C)
ISN to date: 112. At this level SSN
for July 2025 would become: 122.4
(104.0 projected, -4.0) (26.4)
2026.02       (99.9 projected, -4.1)  
2026.03       (95.5 projected, -4.4)  
2026.04       (91.8 projected, -3.7)  
2026.05       (90.5 projected, -1.3)  
2026.06       (88.4 projected, -2.1)  

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz and any corrections applied to that measurement.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days).
2B) Boulder SN current month average to date.
2C) STAR SDO 1K Wolf number 27 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red are based on the definitive international GFZ Potsdam WDC ap indices.
4) Source: WDC-SILSO, Royal Observatory Of Belgium, Brussels

Solar cycles 24-25

Smoothed SF and sunspot numbers

Update on the progress of solar cycle 25 as of October 2025

Sunspot activity was on a decreasing trend from September 2024 until mid August 2025 (using the average solar flux over 3 solar rotations as a proxy). Then a strong surge in activity saw solar flux peak in late August 2025 just below the largest peaks seen in 2024. A slow decrease in activity from the August level has been observed in September and October 2025.

All 365 day smoothed sunspot numbers reached a maximum on October 11-12, 2024
. This became the peak of SC25 (365 day smoothed peaks: STAR 1K: 236.1, STAR 2K: 364.3, NOAA SN: 156.0, ISN: 163.9), while the 365d smoothed solar flux peaked on October 13, 2024, just 1.7% below the SC23 peak, and 62.6% above the SC24 peak.

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This report has been prepared by Jan Alvestad. It is based on the analysis of data from whichever sources are available at the time the report is prepared. All time references are to Universal Time. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.