Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 4, 2026 at 08:55 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 levels on February 3. Solar wind speed at SOHO ranged between 295 and 360 km/sec, averaging 301 km/sec (-5 km/sec compared to the previous day). The high latitude magnetometer at Andenes was at quiet to unsettled 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 177.6 - increasing 42.6 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 150.49 (183 days ago). The 81 day average solar flux at 1 AU was 145.7 (41 days ago, this is 48.5% 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 5 (STAR Ap - based on the average of three hour interval ap indices: 4.6). Three hour interval K indices: 22111121 (planetary), 01112221 (Boulder), 33000331 (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 14 active regions using 2K resolution (SN: 314) and in 10 active regions using 1K resolution (SN: 177) SDO/HMI images.

AR 14358 [N16W31] decayed slowly and quietly.
AR 14360 [S14W23] decayed slowly and quietly.
AR 14362 [S16E06] decayed slowly and quietly.
AR 14363 [S27E08] was quiet and stable.
AR 14366 [N14E07] decayed substantially in the central spot section as the leading and trailing spot sections drifted apart. The region is still very complex with strong magnetic delta configurations in the central and trailing spot sections, however, several smaller magnetic deltas have disappeared. Further major flares are likely.
AR 14367 [N08E35] decayed slowly and quietly.
AR 14368 [S10E38] was quiet and stable.
AR 14369 [S02E44] was quiet and stable.
AR 14370 [S19E51] decayed slowly and quietly.
AR 14371 [S22E59] has many small spots and not much in the way of mature penumbra.
New AR 14372 [S23W39] emerged on February 2 and was numbered the next day by SWPC as the region began to decay.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
New AR S11833 [S29E32] emerged with tiny spots.
New AR S11834 [N28W27] was observed with tiny spots in an old plage area.
New AR S11835 [N10E51] emerged with tiny spots.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C8.6 00:04   14366 GOES18  
C5.9 00:22   14366 GOES18  
C5.6 00:40   14366 GOES18  
C7.8 00:49 N14E24 14366 GOES18  
C8.2 01:07   14366 GOES18  
M1.5/1F 01:49 N12E23 14366 GOES18  
M1.1 02:32   14366 GOES18 simultaneous flare in AR 14367
C4.4 03:32   14366 GOES18  
C3.8 03:53   14366 GOES18  
M1.7/1F 04:22 N12E20 14366 GOES18  
C3.8 05:37   14366 GOES18  
M2.6 05:55 N12E16 14366 GOES18  
M7.2/1N 07:01 N12E16 14366 GOES18  
M3.6/1F 07:47 N12E15 14366 GOES18 simultaneous flare in AR 14371
C7.1 08:35   14366 GOES18  
C6.8 09:14   14366 GOES18  
C5.6 09:49   14366 GOES18  
M3.6/1F 10:12 N14E14 14366 GOES18  
M1.3 11:04   14366 GOES18  
M1.4 11:21   14366 GOES18  
C3.2 12:28   14366 GOES18  
C4.1 12:49   14366 GOES18  
C2.4 13:37   14366 GOES18  
X1.5 14:08   14366 GOES18  
M4.0 14:51   14366 GOES18  
M7.2 14:56   14366 GOES18  
M1.7 15:27   14366 GOES18  
M1.6 15:40   14366 GOES18  
M1.7 15:58   14366 GOES18  
M1.7 16:13   14366 GOES18  
M2.1 16:36   14366 GOES18  
M1.4 16:58   14366 GOES18  
M1.1 17:32   14366 GOES18  
M2.5 18:08   14366 GOES18  
C7.8 19:33   14366 GOES18  
C6.3 20:01   14366 GOES18  
C7.9 20:57   14366 GOES19  
C5.9 21:36   14366 GOES18  
M2.0 22:50   14366 GOES18  
M3.4 23:09 N14E12 14366 GOES18  

Coronal mass ejections (CMEs)

February 3: No obviously Earth directed CMEs were observed in available coronagraph imagery.
February 1-2: A relatively slow moving partial halo CME was observed after the 3 X flares in AR 14366 late on February 1 and early on February 2. The CME could reach Earth on February 5.

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 negative polarity coronal hole (CH1342) could rotate across the central meridian on February 4, however, CH1342 is decaying and was closing on February 3. It is uncertain if there will be any disturbance.

Forecast

The geomagnetic field is expected to be at mostly quiet levels on February 4. Quiet to major storm levels are possible on February 5-6 due to effects associated with the February 1-2 CMEs.

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
14365 2026.01.23
2026.01.30
      N26W66         was AR S11806

location: N28W61

14358 2026.01.26
2026.01.27
5 9 4 N16W30 0030 CRO CRO was AR S11817

location: N16W31

14360 2026.01.27
2026.01.28
  3   S16W29 0004   BXO was AR S11819

location: S14W23

14359 2026.01.27
2026.01.28
      N22W51         was AR S11820

location: N21W50

14362 2026.01.28 7 19 9 S16E06 0040 CAO CAI beta-gamma

was AR S11822

area: 0070

14363 2026.01.28
2026.01.29
  6 1 S26E03 0010   BXO was AR S11823

location: S27E08

14366 2026.01.29
2026.01.30
42 68 40 N14E07 1100 FKC FKC beta-delta-gamma

was AR S11825

area: 1660

S11826 2026.01.29       S22W47          
14367 2026.01.31
2026.01.31
10 17 6 N09E38 0050 CAO CAO was AR S11827

area: 0080

location: N08E35

14368 2026.01.31
2026.01.31
1 4 1 S10E38 0040 HSX CSO was AR S11828

area: 0220

SWPC area is way off

14369 2026.01.31
2026.02.01
1 4 1 S03E43 0040 HSX CSO was AR S11829

area: 0200

SWPC area is way off

14370 2026.02.01
2026.02.02
1 7 3 S18E50 0030 CRO CRO was AR S11830

location: S19E51

area: 0020

SWPC classification is impossible with 1 spot

14371 2026.02.01
2026.02.02
8 22 9 S22E60 0040 DAO DAO was AR S11831

area: 0120

location: S22E59

14372 2026.02.02
2026.02.03
6 10 3 S24W39 0015 BXO BXO was AR S11832

area: 0025

location: S23W39

S11833 2026.02.03   2   S29E32 0004   BXO    
S11834 2026.02.03   1   N28W27 0002   AXX    
S11835 2026.02.03   2   N10E51 0002   AXX    
Total spot count: 81 174 77  
Sunspot number: 171 314 177  (total spot count + 10 * number of spotted regions)
Weighted SN: 124 215 118  (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): 188 173 142  

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
2026.01 149.4 144.0 112.6 (107.2 projected, -3.9) 23.2
2026.02 171.0 (1)   14.3 (2A) / 133.0 (2B) / 142.7 (2C) (103.0 projected, -4.2) (4.5)
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.