Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 16, 2026 at 05:20 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 unsettled to minor storm levels on February 15 under the influence of effects associated with CH1345. Solar wind speed at SOHO ranged between 520 and 732 km/sec, averaging 635 km/sec (+185 km/sec compared to the previous day). The high latitude magnetometer at Andenes was at unsettled to minor 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 117.5 - decreasing 55.9 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 149.46 (183 days ago). The 81 day average solar flux at 1 AU was 148.9 (41 days ago, this is 50.5% 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 26 (STAR Ap - based on the average of three hour interval ap indices: 25.8). Three hour interval K indices: 55333334 (planetary), 55232433 (Boulder), 55533355 (Andenes).

The background x-ray flux is at the class B4 level (GOES 19).

At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 164) and in 9 active regions using 1K resolution (SN: 117) SDO/HMI images.

AR 14373 [N09W56] decayed slowly and quietly.
AR 14374 [N09W11] developed slowly and was mostly quiet. C1 flares: C1.8 @ 21:06 UT
AR 14375 [N16E18] was quiet and stable.
AR 14376 [N12E40] decayed slowly and quietly.
AR 14377 [N08E53] developed further before noon, then began to decay slowly.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S11853 [S12E04] was quiet and stable.
AR S11856 [N19W07] was quiet and stable.
New AR S11862 [N03W17] emerged with tiny spots.
New AR S11863 [N17E10] was observed with tiny spots in an old plage area.
New AR S11864 [N04E35] emerged with a tiny spot.

AR S11854 in the southwest quadrant produced a C1.3 flare at 07:37 UT.

An active region behind the southeast limb produced an M2.4 flare at 04:34 UT on February 16.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment

Coronal mass ejections (CMEs)

February 14-15: No obviously Earth directed CMEs were observed in available coronagraph imagery.
February 13: A poorly defined CME was observed after the M1.0 flare in AR 14373. The CME could reach Earth on February 16.

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) will be Earth facing on February 12-17.

Forecast

The geomagnetic field is expected to be at quiet to minor storm levels on February 16-17 due to effects associated with CH1345, possibly with some contribution on February 16 from the February 13 CME. Quiet to unsettled levels are likely on February 18-20.

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
14373 2026.02.05
2026.02.06
3 6 4 N09W56 0130 HAX CAO

was AR S11836

area: 0160

S11838 2026.02.07       S10W43          
14374 2026.02.08
2026.02.09
2 15 7 N10W11 0200 HSX DHO was AR S11839

area: 0270

location: N09W11

S11842 2026.02.09       S11W26            
S11843 2026.02.09       S23W50            
S11845 2026.02.10       S12W56            
14375 2026.02.10
2026.02.11
1 7 2 N16E18 0020 HRX CRO was AR S11846

area: 0030

14376 2026.02.12
2026.02.14
1 3 1 N13E41 0010 AXX CRO was AR S11851

location: N12E40

S11852 2026.02.12       S12W20            
S11853 2026.02.12   10 1 S12E04 0020   BXO  
S11854 2026.02.13       S14W55          
S11856 2026.02.13   4 2 N19W07 0007   AXX  
S11857 2026.02.13       N21E14            
14377 2026.02.13
2026.02.14
8 13 8 N08E55 0050 CRO DRI was AR S11858

area: 0070

location: N08E53

S11859 2026.02.13       S09E36            
S11860 2026.02.14       S14E57          
S11861 2026.02.14       N38E24          
S11862 2026.02.15   2 1 N03W17 0005   BXO    
S11863 2026.02.15   3 1 N17E10 0006   BXO    
S11864 2026.02.15   1   N04E35 0002   AXX    
Total spot count: 15 64 27  
Sunspot number: 65 164 117  (total spot count + 10 * number of spotted regions)
Weighted SN: 31 88 51  (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): 72 90 94  

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
2026.02 149.9 (1)   58.4 (2A) / 109.0 (2B) / 149.1 (2C) (103.0 projected, -4.2) (11.4)
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.