Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 22, 2026 at 02:50 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 unsettled to severe storm levels on January 21 under the influence of effects from the January 18 CME. Solar wind speed at SOHO ranged between 575 and 915 km/sec, averaging 723 km/sec (-206 km/sec compared to the previous day). The high latitude magnetometer at Andenes was at minor to severe storm levels. The above 10 MeV proton flux decreased gradually and was near 6 pfu at the end of the UT day.

Solar flux density measured at 20h UT on 2.8 GHz was 188.0 - increasing 25.5 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 151.76 (183 days ago). The 81 day average solar flux at 1 AU was 146.0 (41 days ago, this is 48.7% 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 75 (STAR Ap - based on the average of three hour interval ap indices: 75.1). Three hour interval K indices: 77764433 (planetary), 66654333 (Boulder), 77665555 (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 16 active regions using 2K resolution (SN: 374) and in 15 active regions using 1K resolution (SN: 276) SDO/HMI images.

AR 14341 [S10W20] decayed slowly and produced a few C flares towards the end of the day.
AR 14342 [N17W17] was quiet and stable. Note that SWPC groups AR S11780 with this AR.
AR 14343 [S11W70] decayed slowly and quietly.
AR 14344 [N18W28] was quiet and stable.
AR 14345 [S17W16] decayed slowly and lost the magnetic delta configuration
AR 14347 [N10E08] was quiet and stable.
AR 14348 [S17W45] developed slowly as new flux emerged.
AR 14349 [S13E47] produced the largest flare of the day. Slow decay was observed.
AR 14350 [N20E32] decayed slowly and quietly.
AR 14351 [S04E19] developed as new flux emerged. The region has polarity intermixing. There's a chance of a minor M class flare should the development persist.
AR 14352 [S01E09] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S11780 [N12W17] gained a small magnetic delta in the trailing spot section. M class flaring is possible.
AR S11793 [N18E42] was quiet and stable.
New AR S11797 [N17E23] emerged quickly and has polarity intermixing.
New AR S11798 [S13E82] rotated into view with a tiny spot. C1 flares: C1.6 @ 11:42 UT
New AR S11799 [N05W36] emerged with tiny spots.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.1 00:09   S11780 GOES18  
M1.1 01:41 S16W05 14345 GOES18  
C2.0 04:48   14345 GOES18  
C5.1 05:13 southeast limb S11798 GOES18  
C2.8 05:32 southeast limb S11798 GOES18  
M3.4/1B 07:12 S18E62 14349 GOES18  
C2.2 11:57 southeast limb S11798 GOES18  
C3.6 12:12   14345 GOES18  
C2.3 16:33   S11780 GOES18  
C7.0 18:34 S14E55 14349 GOES18  
C3.2 19:10   S11797 GOES18  
C8.6 19:38   14341 GOES18  
C7.6 19:55   14345 GOES18  
C3.2 20:52   14341 GOES18  

Coronal mass ejections (CMEs)

January 19-21: 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) will be Earth facing on January 15-22.

Forecast

The geomagnetic field is expected to be at quiet to active levels on January 22-24 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
S11769 2026.01.13       N08W56            
14341 2026.01.13
2026.01.14
12 34 22 S11W23 0310 DKC DKO

was AR S11770

area: 0410

location: S10W20

14342 2026.01.14
2026.01.14
17 5 3 N14W18 0180 DAI CSO

was AR S11772

area: 0210

location: N17W17

SWPC includes the spots of AR S11780

14343 2026.01.14
2026.01.15
2 5 3 S11W70 0020 CRO HAX

was AR S11774

area: 0040

14344 2026.01.15 1 5 3 N19W29 0010 AXX CRO area: 0015

location: N19W28

14345 2026.01.15
2026.01.15
25 41 23 S17W16 0120 EAI EAI beta-gamma

was AR S11776

area: 0390

14346 2026.01.15
2026.01.15
      S14W07           was AR S11777

location: S13W00

S11779 2026.01.15       N12W34            
S11780 2026.01.15   31 24 N12W17 0280   DAC beta-delta
14347 2026.01.16
2026.01.16
1 10 1 N10E07 0060 HSX HSX was AR S11781

area: 0120

location: N10E08

S11783 2026.01.16       N02W10            
14348 2026.01.18
2026.01.18
  13 9 S18W47 0030   CRI was AR S11784

location: S17W45

14350 2026.01.18
2026.01.19
1 7 3 N21E31 0010 AXX AXX was AR S11786

location: N20E32

14351 2026.01.18
2026.01.19
3 22 16 S04E19 0010 DRO DRO beta-gamma

was AR S11787

area: 0100

S11788 2026.01.18       N04W08          
14349 2026.01.18
2026.01.19
3 10 6 S15E47 0120 DSO CHO was AR S11789

area: 0350

location: S13E47

14352 2026.01.20
2026.01.20
1 3 1 S02E09 0005 AXX BXO was AR S11790

loction: S01E09

S11791 2026.01.20       S05E11          
S11793 2026.01.20   4 2 N18E421 0010   BXO  
S11794 2026.01.20       S14W03          
S11795 2026.01.20       N08W49          
S11797 2026.01.21   20 11 N17E23 0070   DRI    
S11798 2026.01.21   1 1 S13E82 0002   AXX    
S11799 2026.01.21   3   N05E36 0004   BXO    
Total spot count: 66 214 126  
Sunspot number: 166 374 276  (total spot count + 10 * number of spotted regions)
Weighted SN: 102 271 183  (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): 183 206 221  

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
2026.01 147.3 (1)   74.6 (2A) / 110.1 (2B) / 138.5 (2C)
ISN to date: 108. At this level SSN
for July 2025 would become: 122.2
(104.0 projected, -4.0) (26.9)
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.