Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 11, 2025 at 08:00 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 very quiet levels on July 10. Solar wind speed at SOHO ranged between 322 and 386 km/sec, averaging 367 km/sec (-88 km/sec compared to the previous day). The leading part of the disturbance associated with CH1306 began to influence the geomagnetic field early on July 11. The phi angle has since swung into a positive polarity sector. The high latitude magnetometer at Andenes recorded quiet 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 129.5 - decreasing 13.5 over the previous solar rotation. The 365 day average solar flux at 1 AU was 183.91 (183 days ago). The 81 day average solar flux at 1 AU was 138.5 (41 days ago, this is 43.9% 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 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.3). Three hour interval K indices: 11100100 (planetary), 11111321 (Boulder), 21110200 (Andenes).

The background x-ray flux is at the class B9 level (GOES 19).

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 206) and in 10 active regions using 1K resolution (SN: 141) SDO/HMI images.

AR 14132 [S14W70] decayed losing all but tiny leader spots.
AR 14134 [S20W68] developed slowly and was mostly quiet. C1 flares: C1.3 @ 00:57 UT
AR 14135 [S08E28] decayed slowly and quietly.
AR 14136 [N19E56] produced several C flares and has polarity intermixing. C1 flares: C1.3 @ 00:17, C1.1 @ 05:34, C1.3 @ 05:49, C1.7 @ 07:49 UT
AR 14137 [N18W33] developed slowly and was mostly quiet. C1 flares: C1.3 @ 04:36 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S11218 [N08W57] decayed slowly and quietly.
S11236 [N10E25] was quiet and stable.
S11237 [S04E59] was quiet and stable.
S11239 [S08W06] was quiet and stable.
New AR S11240 [N28E03] emerged with several spots. C1 flares: C1.5 @ 23:48 UT
New AR S11241 [N28W02] emerged with tiny spots just west of AR S11240.
New AR S11242 [S14E82] rotated partly into view and produced many C flares. C1 flares: C1.3 @ 02:44, C1.2 @ 02:55, C1.3 @ 09:46, C1.6 @ 21:20, C1.5 @ 22:52 UT

AR 14129 produced a C1.8 flare at 06:53 UT from behind the southwest limb.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.8 06:42   S11242 GOES18  
C4.3 12:04   S11242 GOES18  
C3.4 13:28   S11242 GOES18  
C2.3 13:44   14136 GOES18  
C2.2 14:38   14136 GOES18  
C2.6 15:23   14136 GOES18  
C3.1 16:19   S11242 GOES18  
C3.0 16:47   S11242 GOES18  
C3.1 17:04   14136 GOES18  
C4.2 17:11 N20E55 14136 GOES18  
C3.9 18:04   S11242 GOES18  
C8.9 19:36   S11242 GOES18  
C3.0 19:47   S11242 GOES18  
C2.7 20:30   S11240? GOES18  
C2.5 20:42   14134 GOES18  
C2.1 20:52   14136 GOES18  
C2.1 22:12   S11242 GOES18  

Coronal mass ejections (CMEs)

July 8-10: 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 12-13 due to effects from CH1306. July 14-17 could see unsettled to minor storm levels due to effects associated with CH1306 with the strongest disturbance likely on July 14-15.

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
14132 2025.06.29
2025.07.01
  2 1 S17W63 0004   AXX

was AR S11209

location: S14W70

14130 2025.06.30
2025.06.30
1     S10W65 0010 AXX     was AR S11211

spotless

S11213 2025.06.30       N10W56            
S11218 2025.07.03   2   N08W57 0003   AXX  
S11219 2025.07.03       S05W37            
S11221 2025.07.03       S15W41            
14134 2025.07.05
2025.07.06
1 7 2 S21W73 0010 AXX BXO was AR S11224

location: S20W68

area: 0020

S11225 2025.07.05       N23W57            
14135 2025.07.06
2025.07.07
4 6 3 S09E29 0060 CSO CAO was AR S11226

area: 0130

location: S08E28

S11227 2025.07.06       S26W38            
S11229 2025.07.07       S10W09            
S11230 2025.07.07       S18W34          
14137 2025.07.08
2025.07.09
7 21 14 N18W34 0080 DAO DSI was AR S11231

location: N18W33

area: 0170

14136 2025.07.08
2025.07.09
9 23 12 N19E53 0180 DAI DKC beta-gamma-delta

was AR S11232

location: N19E56

area: 0510

S11233 2025.07.08       N18E14            
S11236 2025.07.09   7 2 N10E25 0020   AXX  
S11237 2025.07.09   1   S04E59 0003   AXX  
S11238 2025.07.09       N13W25          
S11239 2025.07.09   4 1 S08W06 0010   AXX  
S11240 2025.07.10   9 4 N28E03 0030   CRI    
S11241 2025.07.10   2 1 N28W02 0005   BXO    
S11242 2025.07.10   2 1 S14E83 0020   HRX    
Total spot count: 22 86 41  
Sunspot number: 72 206 141  (total spot count + 10 * number of spotted regions)
Weighted SN: 37 112 67  (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): 79 113 113  

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
2025.07 121.9 (1)   32.3 (2A) / 100.1 (2B) / 132.3 (2C) (112.8 projected, -4.2) (12.2)
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.