Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 20, 2025 at 05:05 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 a very quiet level on November 19. Solar wind speed at SOHO ranged between 383 and 490 km/sec, averaging 423 km/sec (-70 km/sec compared to the previous day). The above 10 MeV proton flux was at background levels all day.

Solar flux density measured at 20h UT on 2.8 GHz was 122.5 - decreasing 7.4 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 159.26 (183 days ago). The 81 day average solar flux at 1 AU was 147.2 (41 days ago, this is 49.4% 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 2 (STAR Ap - based on the average of three hour interval ap indices: 2.0). Three hour interval K indices: 00100011 (planetary), 10111211 (Boulder), 10000011 (Andenes).

The background x-ray flux is at the class B7 level (GOES 19).

At the time of counting spots (see image time), spots were observed in 11 active regions using 2K resolution (SN: 168) and in 9 active regions using 1K resolution (SN: 118) SDO/HMI images.

AR 14279 [S13W73] reemerged with tiny spots.
AR 14284 [S07W46] decayed slowly losing spots and area. C1 flares: C1.2 @ 15:13 UT
AR 14285 [S17W56] was quiet and stable.
New AR 14287 [N02E67] rotated into view on November 18 and received its NOAA number the following day.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S11602 [N10W42] was quiet and stable.
AR S11605 [S17W30] was quiet and stable.
AR S11617 [S02W20] was quiet and stable.
AR S11618 [S23W06] was quiet and stable.
AR S11620 [S12W01] was quiet and stable.
New AR S11624 [S01E77] rotated into view with small spots.
New AR S11625 [N21W02] was observed with tiny spots in an old plage area.

AR S11626 is rotating into view at the northeast limb (N17E87) early on November 20, produced a C1.0 flare at 23:14 UT and has M class flare potential.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C9.9 09:53 behind northeast limb S11626 GOES18  

Coronal mass ejections (CMEs)

November 17-19: 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 northern hemisphere negative polarity coronal hole (CH1331) rotated across the central meridian on November 18. A recurrent trans equatorial positive polarity coronal hole (CH1332) will likely become Earth facing on November 22-23.

Forecast

The geomagnetic field is expected to be at quiet levels on November 20. Quiet to active levels are possible from late on November 20 until November 22 due to effects from CH1331.

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
14279 2025.11.07
2025.11.09
  4 2 S12W76 0010   BXO   was AR S11587

location: S13W73

14280 2025.11.09
2025.11.10
      S08W64           was AR S11593

location: S09W56

S11602 2025.11.11   3 1 N10W42 0007   BXO  
S11603 2025.11.12       S06W41            
S11605 2025.11.12   3 1 S17W30 0006   BXO  
S11609 2025.11.14       N24W15            
14283 2025.11.14
2025.11.15
      S19W52         was AR S11610

location: S19W50

14284 2025.11.16
2025.11.16
15 28 17 S07W44 0150 DAI DAI

was AR S11611

area: 0210

14286 2025.11.16
2025.11.18
1     S15E37 0010 AXX     was AR S11613

location: S14E38

spotless

S11614 2025.11.16       N06W30            
S11615 2025.11.16       N14W11            
S11616 2025.11.16       S21E42          
S11617 2025.11.16   2   S02W20 0003   AXX  
S11618 2025.11.16   3 1 S23W06 0012   CRO  
14285 2025.11.17
2025.11.18
3 6 2 S16W55 0010 BXO BXO was AR S11619

location: S17W56

S11620 2025.11.17   3 1 S12W01 0007   BXO  
S11621 2025.11.17       S04W58            
14287 2025.11.18
2025.11.19
1 1 1 N02E65 0090 HSX HSX was AR S11622

area: 0070

location: N02E67

S11623 2025.11.18       N35W01          
S11624 2025.11.19   2 2 S01E77 0010   HRX    
S11625 2025.11.19   3   N21W02 0006   BXO    
Total spot count: 20 58 28  
Sunspot number: 60 168 118  (total spot count + 10 * number of spotted regions)
Weighted SN: 30 74 44  (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): 66 92 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)
2024.07 196.6 203.0 196.8 155.0 (+2.3) 7.13
2024.08  246.1
(SC25 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
2025.11 146.3 (1)   58.4 (2A) / 92.2 (2B) / 119.1 (2C)
ISN average to date: 100
At this level the SSN for May 2025
will become 128.9
(106.8 projected, -2.3) (24.0)
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.

--------------------------------------------------------------------------------------

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.