Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 3, 2025 at 07:00 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 quiet levels on July 2. Solar wind speed at SOHO ranged between 350 and 415 km/sec. Solar wind density was on an increasing trend all day and early on July 3. CIR effects associated with CH1304 have been in progress since late on July 2. The high latitude magnetometer at Andenes recorded quiet to unsettled 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 129.8 - increasing 2.0 over the previous solar rotation. The 365 day average solar flux at 1 AU was 185.16 (183 days ago). The 81 day average solar flux at 1 AU was 141.6 (41 days ago, this is 45.9% 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 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.3). Three hour interval K indices: 21222221 (planetary), 12233222 (Boulder), 32112333 (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 14 active regions using 2K resolution (SN: 238) and in 12 active regions using 1K resolution (SN: 172) SDO/HMI images.

AR 14122 [N11W39] decayed slowly and quietly.
AR 14123 [S28W50] decayed slowly and was mostly quiet. C1 flares: C1.0 @ 12:30 UT.
AR 14124 [S16W15] decayed slowly and quietly.
AR 14125 [N20E08] was mostly quiet and stable.
AR 14126 [N07W80] developed slowly rotated partly out of view. The region was the source of several low level C flares. C1 flares: C1.2 @ 00:30, C1.2 @ 08:37, C1.3 @ 14:37, C1.7 @ 16:12, C1.9 @ 16:24, C1.8 @ 17:32, C1.3 @ 19:23, C1.4 @ 20:15, C1.6 @ 21:24 UT
AR 14127 [S18W06] developed slowly and quietly.
AR 14128 [S05E04] decayed slowly and quietly.
AR 14129 [N01E11] developed slowly and was mostly quiet.
AR 14131 [N07W30] decayed slowly and quietly.
AR 14132 [S18E44] gained a few tiny spots and was mostly quiet. C1 flares: C1.1 @ 11:28, C1.1 @ 22:01 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S11208 [N20W12] was quiet and stable.
S11215 [S21E17] was quiet and stable.
New AR S11216 [S29W63] emerged with tiny spots.
New AR S11217 [S20W01] emerged with several spots just east of AR 14127.

AR 14133 produced a C1.6 flare at 14:56 UT

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 18:08   14126 GOES18  
C2.5 18:35 N07W79 14126 GOES18  

Coronal mass ejections (CMEs)

June 30 - July 2: 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 recurrent negative polarity southern hemisphere coronal hole (CH1304) will be in an Earth facing position on June 29 - July 4. CH1304 has decayed over the last few days due to the development of AR 14127.

Forecast

The geomagnetic field is expected to be at quiet to active levels on July 3-5 due to effects associated with CH1304. There is a chance of isolated minor storm intervals on July 3.

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
14122 2025.06.23
2025.06.25
2 13 5 N12W40 0070 HSX CSO was AR S11188

area: 0170

location: N11W39

14126 2025.06.24
2025.06.28
5 2 1 N07W84 0030 DRO HAX was AR S11190

location: N07W80

area: 0130

S11193 2025.06.25       S14W57            
14124 2025.06.26
2025.06.27
1 4 1 S14W20 0010 AXX BXO

was AR S11198

location: S16W15

14125 2025.06.26
2025.06.27
1 4 1 N21E06 0040 HSX CSO was AR S11199

area: 0100

location: N20E08

14123 2025.06.26
2025.06.27
4 5 4 S28W52 0030 CSO CAO was AR S11200

area: 0040

location: S28W50

14128 2025.06.27
2025.06.29
3 6 4 S05W02 0030 CAO CAO was AR S11202

area: 0050

location: S05E04

SWPC location is way off

14127 2025.06.27
2025.06.29
10 26 17 S18W09 0040 DAI DAI was AR S11203

area: 0220

location: S18W06

14129 2025.06.28
2025.06.30
7 17 9 N02E09 0030 CRI DRO

was AR S11206

location: N01E11

area: 0080

S11207 2025.06.29       S09E10          
S11208 2025.06.29   2   N20W12 0003   AXX  
14132 2025.06.29
2025.07.01
2 7 3 S17E42 0010 AXX CRO beta-gamma

was AR S11209

location: S18E44

area: 0030

S11210 2025.06.29       N25E12            
14130 2025.06.30
2025.06.30
      S12E39         was AR S11211

location: S10E44

14131 2025.06.30
2025.07.01
2 4 2 N08W30 0020 CRO CRO was AR S11212

area: 0030

location: N07W30

S11213 2025.06.30       N11E52            
14133 2025.06.30
2025.07.02
1     S17W79 0005   AXX   was AR S11214

spotless

location: S18W77

S11215 2025.07.01       S19E14          
S11216 2025.07.02   2 2 S29W63 0005   BXO    
S11217 2025.07.02   4 3 S20W01 0020   CRO    
Total spot count: 38 96 52  
Sunspot number: 148 236 172  (total spot count + 10 * number of spotted regions)
Weighted SN: 72 138 94  (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): 163 130 138  

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) 21.2
2025.07 127.8 (1)   9.4 (2A) / 146 (2B) / 134.0 (2C) (112.8 projected, -4.2) (6.1)
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 (STAR 1K 365d peak: 236.1, STAR 2K 365d peak: 364.3, NOAA SN 365d peak: 156.0, ISN 365d peak: 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.