Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 21, 2026 at 07:20 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 (February 2, 2026)
Solar cycle Solar cycles 23-25 (February 1, 2026) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (February 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 (February 1, 2026) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (February 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 active levels on February 20. Weak CME or CIR effects were observed during the latter half of the day with the phi angle moving into a negative sector early on February 21. Solar wind speed at ACE ranged between 443 and 520 km/sec. The high latitude magnetometer at Andenes was at quiet to major storm levels. The above 10 MeV proton flux was at background levels all day.

Solar flux density measured at 20h UT on 2.8 GHz was 111.1 - decreasing 62.4 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 148.60 (183 days ago). The 81 day average solar flux at 1 AU was 146.5 (41 days ago, this is 49.0% 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 10 (STAR Ap - based on the average of three hour interval ap indices: 9.9). Three hour interval K indices: 12222234 (planetary), 13333322 (Boulder), 31222356 (Andenes).

The background x-ray flux is at the class B3 level (GOES 19).

At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 138) and in 7 active regions using 1K resolution (SN: 81) SDO/HMI images.

AR 14374 [N09W77] decayed slowly and quietly.
AR 14375 [N17W45] decayed slowly and quietly.
AR 14376 [N14W28] reemerged with tiny spots.
AR 14377 [N07W17] decayed slowly and quietly.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S11853 [S13W56] decayed slowly and quietly.
AR S11866 [N20E05] was quiet and stable.
AR S11869 [S06E29] was quiet and stable.
AR S11873 [S18E37] was quiet and stable.
New AR S11874 [S14E71] emerged with tiny spots.
New AR S11875 [S13E06] was observed with tiny spots in an old plage area.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.9 03:05 N07E01 14377 GOES18  

Coronal mass ejections (CMEs)

February 18-20: 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 (CH1345) was Earth facing on February 12-18. A recurrent trans equatorial negative polarity coronal hole (CH1346) will rotate across the central meridian on February 20-22.

Forecast

The geomagnetic field is expected to be at quiet to active levels on February 21-22. Quiet to minor storm levels are likely on February 23-25 due to effects associated with CH1346.

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
14374 2026.02.08
2026.02.09
1 2 2 N09W77 0150 HSX CHO

was AR S11839

area: 0260

14375 2026.02.10
2026.02.11
1 3 1 N17W48 0010 AXX AXX was AR S11846

location: N17W45

14376 2026.02.12
2026.02.14
  7   N13W27 0010   BXO   was AR S11851

location: N14W28

S11853 2026.02.12   2   S13W56 0001   BXO  
S11857 2026.02.13       N21W51            
14377 2026.02.13
2026.02.14
2 4 2 N07W16 0010 BXO BXO was AR S11858

location: N07W17

S11859 2026.02.13       S09W03            
S11860 2026.02.14       S14W16          
S11861 2026.02.14       N38W41            
S11863 2026.02.15       N18W56            
S11864 2026.02.15       N04W30            
S11865 2026.02.16       N06W18         merged with AR 14377 on 2026.02.20
S11866 2026.02.16   3 1 N20E05 0006   BXO  
S11867 2026.02.16       S21W47            
S11869 2026.02.17   5 3 S06E29 0010   BXO  
S11871 2026.02.17       S26W27            
S11872 2026.02.18       S05E39            
S11873 2026.02.19   7 1 S18E37 0015   AXX  
S11874 2026.02.20   2   S14E71 0003   BXO    
S11875 2026.02.20   3 1 S13E06 0006   AXX    
Total spot count: 4 38 11  
Sunspot number: 34 138 81  (total spot count + 10 * number of spotted regions)
Weighted SN: 9 48 21  (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): 37 76 65  

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 (-2.3) 11.80
2025.08 154.9 158.7 133.7 (119.9 projected, -2.5) 9.97
2025.09 154.4 156.0 129.7 (117.2 projected, -2.7) 14.02
2025.10 139.5 138.6 114.6 (114.1 projected, -3.1) 15.64
2025.11 140.3 137.3 91.7 (112.4 projected, -1.7) 21.01
2025.12 160.8 155.8 124.0 (111.1 projected, -1.3) 13.35
2026.01 148.7 144.0 112.6 (107.2 projected, -3.9) 22.47
2026.02 143.4 (1)   67.3 (2A) / 94.3 (2B) / 130.9 (2C) (103.0 projected, -4.2) (11.8)
2026.03       (98.4 projected, -4.6)  
2026.04       (94.5 projected, -3.9)  
2026.05       (93.3 projected, -1.2)  
2026.06       (91.1 projected, -2.2)  
2026.07       (86.7 projected, -4.4)  

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.