Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 3, 2025 at 05:25 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 (November 1, 2025)
Solar cycle Solar cycles 23-25 (November 1, 2025) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (November 1, 2025) 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 (November 1, 2025) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (November 1, 2025) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (August 17, 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 November 2 under the influence of effects associated with CH1327. Solar wind speed at SOHO ranged between 488 and 628 km/sec, averaging 558 km/sec (-13 km/sec compared to the previous day). The high latitude magnetometer at Andenes recorded quiet 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 123.0 - decreasing 10.0 over the previous solar rotation.
The 365 day average solar flux at 1 AU was 161.25 (183 days ago). The 81 day average solar flux at 1 AU was 150.0 (41 days ago, this is 51.2% 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 17 (STAR Ap - based on the average of three hour interval ap indices: 17.4). Three hour interval K indices: 44332433 (planetary), 54332322 (Boulder), 54332555 (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: 130) and in 5 active regions using 1K resolution (SN: 73) SDO/HMI images.

AR 14267 [N02W64] decayed slowly with the small spots to the south of the large spot disappearing.
AR 14272 [N21E63] was mostly quiet and stable.
New AR 14273 [S12E27] emerged early in the day and has C flare potential. C1 flares: C1.5 @ 17:11, C1.3 @ 18:25, C1.1 @ 20:30 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S11555 [N12W18] was quiet and stable.
S11562 [S16W29] was quiet and stable.
S11573 [S18W07] was quiet and stable.
New AR S11575 [N23E79] rotated into view as a compact spot group with major flare potential. C1 flares: C1.3 @ 08:38, C1.3 @ 09:29, C1.3 @ 21:55, C1.2 @ 22:21, C1.3 @ 23:15, C1.4 @ 23:26, C1.3 @ 23:43 UT
New AR S11577 [N07E85] rotated into view late in the day with a large spot and produced the only M flare of the day.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
M1.0 00:26 behind northeast limb S11577 GOES18  
C4.6 12:36   S11575 GOES18 LDE
C8.2 12:46 N00W61 14267 GOES18 superimposed on above LDE
C3.8 13:45   S11575 GOES18  
C2.9 14:17   S11575 GOES18  
C2.1 15:02   S11575 GOES18  
C3.7 21:19 N25E76 S11575 GOES18  
C2.8 22:35   S11575 GOES18  
C4.5 00:03   S11575 GOES18 flare began at 23:53 UT

Coronal mass ejections (CMEs)

October 31-November 2: No obviously Earth directed CMEs 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 positive polarity northern hemisphere coronal hole (CH1327) was Earth facing on October 29-30. A negative polarity trans equatorial coronal hole (CH1328) will rotate across the central meridian on November 3-5.

Forecast

The geomagnetic field is expected to be at quiet to active levels on November 3 due to effects associated with CH1327. Mostly quiet conditions are likely on November 4-5. November 6-8 could see unsettled to minor storm levels due to effects from CH1328.

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
14267 2025.10.22
2025.10.23
2 3 1 N02W65 0090 CSO CSO

was AR S11549

area: 0210

location: N02W64

14269 2025.10.24
2025.10.25
      S12W69         was AR S11554

location: S11W66

S11555 2025.10.25   2   N12W18 0002   BXO  
S11562 2025.10.27   2   S16W29 0003   BXO  
S11563 2025.10.27       S02W13            
S11566 2025.10.28       N05W43            
14271 2025.10.28
2025.10.30
      S09E12         was AR S11567

location: S10E19

S11568 2025.10.29       N28W39          
S11569 2025.10.30       N16W48            
S11570 2025.10.30       N20W51            
S11571 2025.10.30       N19W40            
S11572 2025.10.30       S15W44            
S11573 2025.10.30   4   S18W07 0006   BXO  
14272 2025.11.01
2025.11.01
2 6 3 N22E63 0070 CSO CAO was AR S11574

area: 0090

location: N21E63

S11575 2025.11.02   13 6 N23E79 0400   DKC   beta-gamma
14273 2025.11.02
2025.11.02
9 19 12 S12E27 0030 DRI DAI   beta-gamma

was AR S11576

area: 0140

S11577 2025.11.02   1 1 N07E85 0250   HKX    
Total spot count: 13 50 23  
Sunspot number: 43 130 73  (total spot count + 10 * number of spotted regions)
Weighted SN: 26 85 58  (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): 47 72 58  

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)
2024.06 184.3 190.2 164.1 152.8 (+3.7) 10.24
2024.07 196.6 203.0 196.8 155.0 (+2.3) 7.13
2024.08  246.1
(cycle peak)
252.2 216.0  (SC25 peak) 156.8 (+1.8) 15.96
2024.09 195.7 197.8 141.1 159.4 (+1.6) 15.36
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 projected, -4.8) 17.26
2025.06 131.3 135.4 114.6 (123.8 projected, -4.7) 21.43
2025.07 137.8 142.3 125.6 (120.6 projected, -3.2) 11.80
2025.08 154.9 158.7 133.5 (117.0 projected, -3.6) 9.97
2025.09 154.4 156.0 129.8 (113.1 projected, -3.9) 14.1
2025.10 139.5 138.6 114.6 (109.1 projected, -4.0) 15.9
2025.11 119.2 (1)   2.2 (2A) / 33.5 (2B) / 129.3 (2C) (106.8 projected, -2.3) (14.6)
2025.12       (105.3 projected, -1.5)  
2026.01       (101.2 projected, -4.1)  
2026.02       (97.1 projected, -4.1)  
2026.03       (92.8 projected, -4.3)  
2026.04       (89.0 projected, -3.8)  

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.