Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 12, 2025 at 06:40 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 (June 1, 2025)
Solar cycle Solar cycles 23-25 (June 1, 2025) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (June 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 (June 1, 2025) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (June 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 Research: Solar Cycle 25 Started on November 17, 2019 with 365 Days Smoothing
Calculating the Strength of Solar Cycle 25 Using 365-day Smoothing

Recent activity

The geomagnetic field was at quiet to active levels on June 11. A disturbance started after 15h UT, the source is uncertain. Solar wind speed at SOHO ranged between 398 and 486 km/sec, averaging 436 km/sec (+9 km/sec compared to the previous day). The high latitude magnetometer at Andenes recorded quiet to major 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 141.8- increasing 23.0 over the previous solar rotation. The 365 day average solar flux at 1 AU was 188.20 (183 days ago). SC25 365d peak: 195.86 on October 13, 2024. The Potsdam WDC planetary A index was 16 (STAR Ap - based on the mean of three hour interval ap indices: 15.8). Three hour interval K indices: 33112444 (planetary), 33222453 (Boulder), 54123546 (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 17 active regions using 2K resolution (SN: 333) and in 15 active regions using 1K resolution (SN: 228) SDO/HMI images.

AR 14105 [S15W32] gained a small magnetic delta configuration in the trailing spot section. Flare frequency increased compared to the previous days, however, all flares were at the C level, and most of then low level. C1 flares: C1.8 @ 04:43, C1.9 @ 06:08, C1.6 @ 07:56 UT
AR 14108 [S20W75] decayed slowly and quietly.
AR 14109 [S14W21] decayed slowly and quietly.
AR 14110 [N05W18] decayed slowly and quietly.
AR 14111 [N14E40] was mostly quiet and stable.
AR 14112 [S08E20] has many tiny spots and was quiet.
New AR 14113 [N10E61] rotated into view on June 10 and was numbered the next day by SWPC.
New AR 14114 [N17E65] rotated into view on June and received its NOAA number the next day as slow development continued. C1 flares: C1.0 @ 00:52 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S11120 [N12W33] was quiet and stable.
S11145 [S14W52] slowed its development and still has a significant magnetic delta configuration. A major flare is possible. SWPC moved AR 14107 to this region on June 10. C1 flares: C1.2 @ 00:32, C1.0 @ 01:58, C1.8 @ 02:29, C1.1 @ 04:08, C1.5 @ 09:05, C1.3 @ 10:05, C1.6 @ 11:34, C1.8 @ 15:00 UT
S11148 [N21E03] was quiet and stable.
New region S11151 [N20E77] rotated into view with a few spots. C1 flares: C1.1 @ 01:21, C1.4 @ 02:40, C1.6 @ 11:17 UT
New region S11152 [N15E13] emerged with tiny spots.
New region S11153 [S34E05] emerged with a tiny spot.
New region S11154 [S32W13] emerged with a tiny spot.
New region S11155 [N04E18] was observed with tiny spots in an old plage area.
New region S11156 [S16W41] emerged with tiny spots.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.1 04:48   S11151 GOES18  
C2.6 05:42   S11145 GOES18  
C2.3 07:10   S11151 GOES18  
C2.1 08:44   S11145 GOES18  
C2.5 12:32 S16W26 14105 GOES18  
C2.1 14:31   14114 GOES18  
C3.9 15:40   14105 GOES18  
C6.3 15:52   S11145 GOES18  
C4.7 16:16   S11145 GOES18  
C4.6 16:23   S11145 GOES18  
C4.1 16:37   S11145 GOES18  
C5.1 17:09   S11145 GOES18  
C4.2 17:35   S11151 GOES18  
C4.3 19:03   S11145 GOES18  
C8.5 19:11   S11151 GOES18  
C5.0 19:16   S11151 GOES18  
C3.4 20:41   S11145 GOES18  
C3.2 22:51   S11145 GOES18  
C3.2 23:46   S11145 GOES18  

Coronal mass ejections (CMEs)

June 10-12: No obviously Earth directed CMEs.
June 9: A filament eruption from just north of AR 14105 and extending well into the northeast quadrant was observed beginning early in the day and peaking near 08h UT. A partial halo CME was seen in LASCO imagery, components of the CME could reach Earth on June 12-13.

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 negative polarity trans equatorial coronal hole (CH1300) rotated across the central meridian on June 8. A large recurrent positive polarity southern hemisphere coronal hole (CH1301) will be Earth facing on June 11-18.

Forecast

The geomagnetic field is expected to be at quiet to active levels on June 12-13 due to effects from CH1300 and possibly the June 9 CME. Quiet to minor storm levels will be possible on June 14-20 due to effects from CH1301.

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
14105 2025.06.02
2025.06.03
15 55 31 S14W32 0250 EKC EAC

was AR S11119

area: 0420

location: S15W32

S11120 2025.06.02   2   N12W33 0003   AXX  
14106 2025.06.03
2025.06.04
      N13W83           was AR S11123

location: N13W78

14107 2025.06.05
2025.06.06
8     S14W54 0180 DAO       was AR S11129

location: S19W56

spotless

SWPC location on June 9: S18W31. On June 10 SWPC moved this region to the spots of AR S11145

14109 2025.06.05
2025.06.07
3 12 3 S17W18 0010 CRO CRO was AR S11131

area: 0025

location: S14W21

14108 2025.06.06
2025.06.07
1 3 2 S21W71 0010 AXX BXO was AR S11133

location: S20W75

S11135 2025.06.06       S14W48            
S11136 2025.06.07       N25W47            
S11138 2025.06.07       S03W16            
14111 2025.06.08
2025.06.09
2 5 1 N16E41 0140 HSX CSO was AR S11139

area: 0210

loction: N14E40

14110 2025.06.08
2025.06.09
4 18 6 N05W16 0010 CRO CRO beta-gamma

was AR S11140

area: 0050

location: N05W18

14112 2025.06.08 1 23 10 S09E25 0005 AXX BXO was AR S11141

area: 0040

location: S08E20

S11142 2025.06.08       S24W31            
S11143 2025.06.08       S22W09            
S11145 2025.06.09   16 10 S14W52 0260   DKC beta-delta

this became AR 14107 to SWPC on 2025.06.10

S11146 2025.06.09       N03W26            
S11147 2025.06.09       S27W39            
S11148 2025.06.10   1 1 N21E03 0002   AXX  
14113 2025.06.10
2025.06.11
3 4 2 N12E65 0020 CAO CAO was AR S11149

location: N10E61

area: 0050

14114 2025.06.10
2025.06.11
6 10 5 N17E65 0030 CRO DRI was AR S11150

area: 0050

S11151 2025.06.11   3 2 N20E77 0250   DSO    
S11152 2025.06.11   2 2 N15E13 0010   BXO    
S11153 2025.06.11   1 1 S34E05 0003   AXX    
S11154 2025.06.11   2 1 S32W13 0004   AXX    
S11155 2025.06.11   4   N04E18 0005   BXO    
S11156 2025.06.11   2 1 S16W41 0005   BXO    
Total spot count: 43 163 78  
Sunspot number: 133 333 228  (total spot count + 10 * number of spotted regions)
Weighted SN: 77 202 117  (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): 146 183 182  

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 (150.7 projected, -6.3) 8.42
2025.01 190.3 184.2 137.0 (144.2 projected, -6.5) 13.17
2025.02  184.2 179.7 154.6 (135.6 projected, -8.6) 14.42
2025.03 163.7 162.1 134.2 (129.2 projected, -6.4) 15.96
2025.04 162.5 163.6 140.6 (124.6 projected, -4.6) 17.62
2025.05  135.3 138.3 79.2 (119.3 projected, -5.3) 17.26
2025.06 130.5 (1)   35.6 (2A) / 97.0 (2B) / 118.7 (2C) (114.4 projected, -4.9) (30.5)
2025.07       (110.2 projected, -4.2)  
2025.08       (105.5 projected, -4.7)  
2025.09       (101.2 projected, -4.3)  
2025.10       (97.3 projected, -3.9)  
2025.11       (95.0 projected, -2.3)  

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 May 13, 2025

Sunspot activity has been on a slowly decreasing trend since September 2024 (using the average solar flux over 3 solar rotations as a proxy). The decline has become more obvious during the first half of May 2025 with solar flux on May 12 at its lowest level since April 4, 2024. The solar max phase of solar cycle 25 was considerably shorter than that of the most recent solar cycles.

All 365 days 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.