Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 11, 2026 at 06:15 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 10, likely under the influence of effects associated with CH1343. Solar wind speed at SOHO ranged between 379 and 504 km/sec, averaging 433 km/sec (+45 km/sec compared to the previous day). 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 142.1 - increasing 15.6 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 150.12 (183 days ago). The 81 day average solar flux at 1 AU was 148.7 (41 days ago, this is 50.4% 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: 9.5). Three hour interval K indices: 10132134 (planetary), 10133333 (Boulder), 20021246 (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 15 active regions using 2K resolution (SN: 247) and in 10 active regions using 1K resolution (SN: 142) SDO/HMI images.

AR 14366 [N15W79] rotated partly out of view producing several M flares late in the day and early on February 11. C1 flares: C1.7 @ 01:28, C1.2 @ 02:28, C1.5 @ 04:07, C1.3 @ 05:17, C1.9 @ 10:59, C1.5 @ 11:41, C1.3 @ 12:20, C1.4 @ 13:55, C1.3 @ 15:18, C1.5 @ 15:54, C1.3 @ 16:33, C1.4 @ 22:14 UT
AR 14367 [N08W58] decayed slowly and quietly.
AR 14368 [S09W54] was quiet and stable.
AR 14369 [S03W50] was quiet and stable.
AR 14371 [S23W35] decayed slowly and was mostly quiet.
AR 14373 [N08E11] was quiet and stable.
AR 14374 [N10E55] was mostly quiet and stable. C1 flares: C1.5 @ 17:24 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S11838 [S09E20] was quiet and stable.
AR S11841 [S15W02] reemerged with a tiny spot.
AR S11843 [S23E13] was quiet and stable.
New AR S11844  [S19W69] emerged with tiny spots.
New AR S11845 [S11E09] emerged with tiny spots.
New AR S11846 [N15E84] rotated partly into view.
New AR S11847 [S18W53] emerged with tiny spots.
New AR S11848 [N15W35] emerged with a tiny spot.

AR 14370 produced a C1.4 flare at 03:52 and a C1.2 flare at 04:40 UT.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.6 00:34   14366 GOES18  
C2.6 00:47   14366 GOES18  
C2.3 05:48   14366 GOES18  
C2.3 06:17   14366 GOES18  
C3.6 06:48   14370 GOES18  
C3.9 07:04   14366 GOES18  
C2.5 08:09   14374 GOES18  
C3.2 08:20   14374 GOES18  
C2.2 08:52   14366 GOES18  
C2.5 13:06   14366 GOES18  
C3.1 19:10   14366 GOES18  
M1.2 00:09   14366 GOES18 flare started at 23:59 UT

Coronal mass ejections (CMEs)

February 8-10: 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 northern hemisphere negative polarity coronal hole (CH1343) rotated across the central meridian on February 5-8. A recurrent trans equatorial negative polarity coronal hole (CH1344) was Earth facing on February 6. A recurrent southern hemisphere positive polarity coronal hole (CH1345) will likely become Earth facing on February 12-14.

Forecast

The geomagnetic field is expected to be at quiet to active levels on February 11 due to effects associated with CH1343/CH1344 and quiet on February 12-14.

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
14362 2026.01.28       S18W88          

was AR S11822

location: S18W84

14366 2026.01.29
2026.01.30
22 15 9 N14W84 0800 FHC EAC beta-delta

was AR S11825

area: 0350

SWPC spot count unchanged from previous day

14367 2026.01.31
2026.01.31
1 4 3 N09W58 0015 HRX BXO

was AR S11827

location: N08W58

14368 2026.01.31
2026.01.31
1 2 1 S10W55 0100 HSX HSX was AR S11828

area: 0170

location: S09W54

14369 2026.01.31
2026.02.01
2 5 4 S03W51 0110 HSX CSO was AR S11829

area: 0160

location: S03W50

14370 2026.02.01
2026.02.02
      S18W45         was AR S11830

location: S19W41

14371 2026.02.01
2026.02.02
1 9 2 S23W34 0020 HRX CRO

was AR S11831

location: S23W33

S11835 2026.02.03       N11W41            
14373 2026.02.05
2026.02.06
3 23 7 N09E10 0140 HAX CSO

beta-gamma

was AR S11836

area: 0220

location: N08E11

S11837 2026.02.07       S12W13            
S11838 2026.02.07   12 3 S09E20 0020   BXO  
14374 2026.02.08
2026.02.09
5 9 7 N11E58 0200 CSO EHO was AR S11839

area: 0280

location: N10E55

S11840 2026.02.08       S31W37            
S11841 2026.02.09   1   S15W02 0002   AXX    
S11842 2026.02.09       S11E39          
S11843 2026.02.09   4   S23E15 0007   AXX  
S11844 2026.02.10   6 3 S19W69 0020   BXO    
S11845 2026.02.10   3 3 S11E09 0020   DRO    
S11846 2026.02.10   1   N15E84 0050   HAX    
S11847 2026.02.10   2   S18W53 0003   BXO    
S11848 2026.02.10   1   N15W35 0001   AXX    
Total spot count: 35 97 42  
Sunspot number: 105 247 142  (total spot count + 10 * number of spotted regions)
Weighted SN: 71 138 83  (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): 116 136 114  

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
2026.02 164.0 (1)   46.2 (2A) / 129.4 (2B) / 151.7 (2C) (103.0 projected, -4.2) (9.6)
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.