Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 13, 2025 at 07:05 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 (July 1, 2025)
Solar cycle Solar cycles 23-25 (July 1, 2025) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (July 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 (July 1, 2025) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (July 1, 2025) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (April 21, 2025) Cycle 25 spots (final update December 25, 2019)
  Solar cycles 24-25 transition using 365d smoothing  

Recent activity

The geomagnetic field was at quiet to unsettled levels on July 12 under the influence of effects associated with CH1306. A significant increase in disturbance levels was observed early on July 13 as the trans equatorial part of CH1306 became geoeffective. Solar wind speed at SOHO ranged between 405 and 603 km/sec, averaging 484 km/sec (+56 km/sec compared to the previous day). The high latitude magnetometer at Andenes recorded unsettled to active 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 138.7 - decreasing 21.8 over the previous solar rotation. The 365 day average solar flux at 1 AU was 183.51 (183 days ago). The 81 day average solar flux at 1 AU was 137.9 (41 days ago, this is 43.5% of the 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: 195.86 on October 13, 2024. The Potsdam WDC planetary A index was 12 (STAR Ap - based on the mean of three hour interval ap indices: 12.0). Three hour interval K indices: 33333223 (planetary), 33434323 (Boulder), 43333333 (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 12 active regions using 2K resolution (SN: 257) and in 10 active regions using 1K resolution (SN: 167) SDO/HMI images.

AR 14135 [S08E02] was quiet and stable.
AR 14136 [N19E28] decayed slowly and was mostly quiet. C1 flares: C1.2 @ 21:02 UT
AR 14137 [N18W62] was mostly quiet and stable.
AR 14138 [N28W26] gained area and extended longitudinally with greater separation between the leading and trailing spot sections. The region was mostly quiet.
AR 14139 [N21E10] developed slowly and was mostly quiet. Minor polarity intermixing is present. C1 flares: C1.8 @ 01:02, C1.6 @ 02:33 UT
AR 14140 [S16E62] still has a magnetic delta configuration and was by far the most active region on the visible disk producing many C and M flares. C1 flares: C1.3 @ 00:45, C1.4 @ 01:30, C1.6 @ 02:39, C1.9 @ 11:41, C1.6 @ 17:57, C1.5 @ 21:08 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S11236 [N10W01] was quiet and stable.
S11237 [S04E38] reemerged with tiny spots.
New AR S11245 [S13W62] emerged with several spots.
New AR S11246 [S14W73] emerged with a tiny spot.
New AR S11247 [N25E31] was split off from AR 14136.
New AR S11248 [N18W50] was observed with tiny spots in an old plage area.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.3 02:14   14140 GOES18  
C2.1 03:08   14140 GOES18  
C2.0 03:23 behind SW limb 14134 GOES18  
C4.1 03:39   14140 GOES18  
C2.3 03:50   14140 GOES18  
M1.4 04:02   14140 GOES18  
C2.9 06:08   14138 GOES18  
C3.9 06:53   14138 GOES18 simultaneous flare in AR 14140
C2.6 07:46     GOES18  
C4.8 08:20 S14E72 14140 GOES18  
M2.3/1F 08:34 S14E72 14140 GOES18  
C4.0 09:17   14138 GOES18  
M1.6/1F 12:10 S15E70 14140 GOES18  
C3.4 12:48 S15E70 14140 GOES18  
C2.7 14:21 S15E70 14140 GOES18  
C5.3 15:07 behind SW limb 14134 GOES18  
C3.2 15:56 behind SW limb 14134 GOES18  
C7.0/1F 18:35 N20E25 14136 GOES18  
C5.5 22:02 S14E66 14140 GOES18  

Coronal mass ejections (CMEs)

July 10-12: No obviously Earth directed CMEs.

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 huge recurrent trans equatorial positive polarity coronal hole (CH1306) will be Earth facing on July 8-15.

Forecast

The geomagnetic field is expected to be quiet to minor storm on July 13-15 due to effects from CH1306. Quiet to unsettled levels are likely on July 16-18.

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
14135 2025.07.06
2025.07.07
1 7 3 S08E01 0050 HSX CSO was AR S11226

area: 0110

location: S08E02

S11229 2025.07.07       S10W35            
14137 2025.07.08
2025.07.09
5 16 6 N18W61 0060 DAI DAI was AR S11231

location: N18W62

area: 0120

14136 2025.07.08
2025.07.09
8 19 9 N19E27 0200 DAO EKC beta-delta

was AR S11232

location: N19E28

area: 0470

S11233 2025.07.08       N18W12            
S11236 2025.07.09   14 7 N10W01 0030   AXX  
S11237 2025.07.09   3   S04E38 0004   BXO    
S11238 2025.07.09       N13W51            
S11239 2025.07.09       S08W32            
14138 2025.07.10
2025.07.11
8 20 11 N28W26 0200 DAI EAO

was AR S11240

area: 0420

14140 2025.07.10
2025.07.11
6 15 7 S15E61 0130 DAO DAC beta-delta

was AR S11242

area: 0300

14139 2025.07.11
2025.07.11
5 24 14 N22E10 0060 DAI DAI beta-gamma

was AR S11243

area: 0170

S11244 2025.07.11       N23E42          
S11245 2025.07.12   8 5 S13W62 0080   DAI    
S11246 2025.07.12   1 1 S14W73 0003   AXX    
S11247 2025.07.12   8 4 N25E31 0020   BXO    
S11248 2025.07.12   2   N18W50 0002   AXX    
Total spot count: 33 137 67  
Sunspot number: 93 257 167  (total spot count + 10 * number of spotted regions)
Weighted SN: 63 177 107  (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): 102 141 134  

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2024.01 164.6 159.3 126.0 131.2 (+1.7) 5.46
2024.02 172.5 168.3 123.0 136.9 (+5.7) 5.31
2024.03 154.4 152.9 103.7 141.4 (+4.5) 11.03
2024.04 161.3 162.6 137.0 144.5 (+3.1) 9.69
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
2024.10 221.0 219.6 165.8 160.8 (+1.4) (SC25 solar max) 18.99
2024.11 199.6 195.3 154.1 157.0 (-3.8) 9.33
2024.12 197.3 191.2 154.6 151.2 (-5.8) 8.42
2025.01 190.3 184.2 137.0 (146.0 projected, -5.2) 13.17
2025.02  184.2 179.7 154.6 (138.2 projected, -7.8) 14.42
2025.03 163.7 162.1 134.2 (131.8 projected, -6.4) 15.96
2025.04 162.5 163.6 140.6 (127.2 projected, -4.6) 17.62
2025.05  135.3 138.3 79.2 (121.9 projected, -5.3) 17.26
2025.06 131.3 135.4 116.3 (117.0 projected, -4.9) 21.43
2025.07 124.1 (1)   38.5 (2A) / 99.3 (2B) / 129.6 (2C) (112.8 projected, -4.2) (12.5)
2025.08       (108.1 projected, -4.7)  
2025.09       (103.8 projected, -4.3)  
2025.10       (99.9 projected, -3.9)  
2025.11       (97.6 projected, -2.3)  
2025.12       (96.0 projected, -1.6)  

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 June 23, 2025

Sunspot activity has been on a decreasing trend since September 2024 (using the average solar flux over 3 solar rotations as a proxy). Compared to the peak of SC25 solar flux has been at a low level in both May and June 2025. Taking a closer look at the 81 day (3 solar rotations) average solar flux proxy, its peak was in early September 2024 and had on May 12 decreased to less than half of the solar cycle flux range. Subtracting the 81 day average of approximately 69 at solar cycle minimum from all measurements, the SC25 range is 0 - 158.3.

All 365 day smoothed sunspot numbers peaked on October 11-12, 2024
, very likely making this the peak of SC25 (365 day smoothed peaks: STAR 1K: 236.1, STAR 2K: 364.3, NOAA SN: 156.0, ISN: 163.6). 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.