Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 14, 2025 at 07:55 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 (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 unsettled to active levels on July 13 under the influence of effects associated with CH1306. Solar wind speed at SOHO ranged between 547 and 752 km/sec, averaging 618 km/sec (+134 km/sec compared to the previous day). The high latitude magnetometer at Andenes recorded active to severe 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 128.2 - decreasing 19.7 over the previous solar rotation. The 365 day average solar flux at 1 AU was 183.19 (183 days ago). The 81 day average solar flux at 1 AU was 137.4 (41 days ago, this is 43.2% 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 21 (STAR Ap - based on the mean of three hour interval ap indices: 21.3). Three hour interval K indices: 44334333 (planetary), 44454333 (Boulder), 67444455 (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 13 active regions using 2K resolution (SN: 280) and in 12 active regions using 1K resolution (SN: 195) SDO/HMI images.

AR 14135 [S08W11] was quiet and stable.
AR 14136 [N20E17] decayed losing the magnetic delta configuration.
AR 14137 [N18W78] decayed slowly and was mostly quiet.
AR 14138 [N28W40] gained spots and was quiet.
AR 14139 [N21W04] developed slowly and was mostly quiet.
AR 14140 [S15E48] decayed slightly, however, there are still small magnetic delta configurations in the trailing spot section. C1 flares: C1.2 @ 00:50, C1.4 @ 02:05, C1.5 @ 02:12, C1.7 @ 02:17, C1.5 @ 02:30, C1.6 @ 02:40, C1.1 @ 03:22, C1.0 @ 16:48, C1.1 @ 19.09, C1.3 @ 22:42, C1.3 @ 23:40 UT
New AR 14141 [S13W75] emerged on July 12 and was numbered the next day by SWPC as the region began to decay.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S11236 [N10W06] was quiet and stable.
New AR S11249 [N30W18] emerged with tiny spots.
New AR S11250 [S17W71] emerged with tiny spots.
New AR S11251 [S09E24] emerged with a tiny spot.
New AR S11252 [N01E62] emerged with several spots and has polarity intermixing.C1 flares: C1.1 @ 17:08, C1.0 @ 20:32, C1.3 @ 22:54 UT
New AR S11253 [S06W24] emerged with a tiny spot.

A C1.4 flare was recorded at 21:41 UT from a location behind the southwest limb.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.8 03:56   14140 GOES18  
C8.9 04:02   14140 GOES18  
C3.1 05:55 S13E59 14140 GOES18  
C2.4 06:47 S13E59 14140 GOES18  
C2.9 18:09   14140 GOES18  
C8.9 21:50 behind southwest limb   GOES18 simultaneous flares in ARs 14140 and S11252
C2.7 23:17   14140 GOES18  
C2.5 23:59   S11252 GOES18  

Coronal mass ejections (CMEs)

July 11-13: 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 8-16.

Forecast

The geomagnetic field is expected to be quiet to active levels on July 14-15 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 5 3 S09W12 0060 HSX CSO was AR S11226

area: 0120

location: S08W11

S11229 2025.07.07       S10W48            
14137 2025.07.08
2025.07.09
4 10 5 N19W74 0040 CSO CAO was AR S11231

location: N18W78

area: 0100

14136 2025.07.08
2025.07.09
4 29 16 N19E13 0190 DAO EHO beta-gamma

was AR S11232

location: N20E17

area: 0440

S11233 2025.07.08       N18W25            
S11236 2025.07.09   11 3 N10W06 0020   AXX  
S11237 2025.07.09       S04E25          
S11239 2025.07.09       S08W45            
14138 2025.07.10
2025.07.11
8 29 14 N29W39 0200 DAO EAI

was AR S11240

area: 0400

14140 2025.07.10
2025.07.11
6 21 10 S15E46 0090 CAO DAC beta-gamma-delta

was AR S11242

area: 0180

location: S15E48

14139 2025.07.11
2025.07.11
6 24 16 N22W04 0100 DAI DAI

was AR S11243

area: 0210

S11244 2025.07.11       N23E29            
14141 2025.07.12
2025.07.13
3 6 2 S13W76 0030 CAO BXO was AR S11245

location: S13W75

area: 0020

S11247 2025.07.12       N25E18          
S11249 2025.07.13   2 1 N30W18 0003   BXO    
S11250 2025.07.13   2 1 S17W71 0005   AXX    
S11251 2025.07.13   1 1 S09E24 0003   AXX    
S11252 2025.07.13   9 5 N01E62 0040   DRI    
S11253 2025.07.13   1   S06W24 0001   AXX    
Total spot count: 32 150 75  
Sunspot number: 102 280 195  (total spot count + 10 * number of spotted regions)
Weighted SN: 67 188 113  (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): 112 154 156  

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
2024.10 221.0 219.6 165.8 160.9 (+1.5) (SC25 solar max) 18.99
2024.11 199.6 195.3 154.1 157.1 (-3.8) 9.33
2024.12 197.3 191.2 154.6 151.3 (-5.8) 8.42
2025.01 190.3 184.2 137.0 (146.1 projected, -5.2) 13.17
2025.02  184.2 179.7 155.7 (138.3 projected, -7.8) 14.42
2025.03 163.7 162.1 134.2 (131.9 projected, -6.4) 15.96
2025.04 162.5 163.6 140.6 (127.3 projected, -4.6) 17.62
2025.05  135.3 138.3 79.2 (122.0 projected, -5.3) 17.26
2025.06 131.3 135.4 116.3 (117.1 projected, -4.9) 21.43
2025.07 124.5 (1)   41.7 (2A) / 99.5 (2B) / 129.6 (2C) (112.9 projected, -4.2) (13.2)
2025.08       (108.1 projected, -4.8)  
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: 163.9). 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.