Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 15, 2026 at 04:35 UT. Active region table to be updated

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 unsettled levels on January 14. Solar wind speed at SOHO ranged between 464 and 581 km/sec, averaging 500 km/sec (-47 km/sec compared to the previous day). The above 10 MeV proton flux was at background levels all day.

Solar flux density measured at 20h UT on 2.8 GHz was 126.5 - increasing 10.6 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 152.73 (183 days ago). The 81 day average solar flux at 1 AU was 142.2 (41 days ago, this is 46.3% 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 7 (STAR Ap - based on the average of three hour interval ap indices: 6.6). Three hour interval K indices: 22112123 (planetary), 11112222 (Boulder), 43011134 (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 8 active regions using 2K resolution (SN: 174) and in 8 active regions using 1K resolution (SN: 131) SDO/HMI images.

AR 14336 [S09W57] decayed slowly and quietly.
AR 14339 [S12W62] was quiet and stable.
AR 14340 [N14E07] gained a magnetic delta configuration in the trailing spot section. A minor M flare is possible. C1 flares: C1.3 @ 00:03, C1.0 @ 12:38, C1.2 @ 18:49, C1.4 @ 22:54 UT
New AR 14341 [S10E71] rotated into view on January 14 and was numbered the next day by SWPC. The region is compact and has major flare potential. C1 flares: C1.0 @ 01:10, C1.2 @ 06:28, C1.1 @ 08:55, C1.1 @ 13:08, C1.5 @ 14:26, C1.0 @ 17:44, C1.7 @ 19:17 UT
New AR 14342 [N17E73] rotated into view with mature spots. C1 flares: C1.3 @ 00:19, C1.8 @ 03:44, C1.9 @ 09:53, C1.0 @ 10:41, C1.0 @ 13:21, C1.2 @ 15:24, C1.9 @ 23:26 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S11769 [N11E35] was quiet and stable.
New AR S11773 [N12E22] emerged with a tiny spot.
New AR S11774 [S10E20] emerged before noon and developed quickly.

A C1.5 flare was recorded at 07:19 UT and has not been attributed to any AR due to lack of imagery.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C9.6 03:50   14342 GOES18  
C2.5 04:16   14342 GOES18  
C3.6 16:17   14342 GOES18  
M1.6/1F 20:33 S14E73 14341 GOES18  
C3.8 23:56   14340 GOES18  

Coronal mass ejections (CMEs)

January 12-14: 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 recurrent trans equatorial positive polarity coronal hole (CH1340) will likely become Earth facing on January 15-18.

Forecast

The geomagnetic field is expected to be at quiet to unsettled levels on January 15-16. Effects assocatied with CH1340 could cause unsettled to minor storm levels on January 17-20.

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
14334 2026.01.01
2026.01.02
1 2 1 S16W70 0010 AXX AXX

was AR S11740

area: 0005

location: S16W69

14336 2026.01.04
2026.01.04
12 22 13 S09W39 0250 EHO CKO

was AR S11747

area: 0400

location: S09W43

14338 2026.01.06
2026.01.08
      S06W39           was AR S11754

location: S05W31

S11755 2026.01.07       N16W53            
14339 2026.01.08
2026.01.09
  2   S13W51 0002   BXO   was AR S11756

location: S14W48

14340 2026.01.10
2026.01.11
6 24 13 N14E17 0030 CSO DAI beta-gamma

was AR S11760

area: 0110

location: N14E20

S11761 2026.01.10       N16E18           merged with AR S11760
S11762 2026.01.11       N08W39            
S11763 2026.01.11       N01W49            
S11764 2026.01.11   2 2 S15E17 0005   AXX    
S11765 2026.01.12       S02W58          
S11766 2026.01.12   2   N27E05 0003   BXO  
S11767 2026.01.12       N08W08          
S11768 2026.01.13   2 1 N11W24 0005   BXO    
S11769 2026.01.13   5 2 N11E49 0010   BXO    
S11770 2026.01.13   5 4 S10E83 1050   DKC    
Total spot count: 19 66 36  
Sunspot number: 49 156 106  (total spot count + 10 * number of spotted regions)
Weighted SN: 34 91 61  (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): 54 86 85  

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 78.5 128.5 (-4.8) 17.26
2025.06 131.3 135.4 114.6 124.7 (-3.8) 21.43
2025.07 137.8 142.3 125.6 (122.4 projected, -2.3) 11.80
2025.08 154.9 158.7 133.5 (119.3 projected, -3.1) 9.97
2025.09 154.4 156.0 129.8 (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 (109.5 projected, -2.3) 21.01
2025.12 160.8 155.8 124.0 (108.0 projected, -1.5) 13.35
2026.01 138.0 (1)   39.1 (2A) / 93.2 (2B) / 118.3 (2C) (104.0 projected, -4.0) (14.1)
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.