Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 13, 2025 at 06:05 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 (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 unsettled to minor storm levels on June 12. Early on June 13 the geomagnetic field appears to be under the influence of CIR effects related to CH1301. Solar wind speed at SOHO ranged between 382 and 476 km/sec, averaging 432 km/sec (-4 km/sec compared to the previous day). The high latitude magnetometer at Andenes recorded active to minor 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 141.5 - increasing 24.2 over the previous solar rotation. The 365 day average solar flux at 1 AU was 188.14 (183 days ago). SC25 365d peak: 195.86 on October 13, 2024. The Potsdam WDC planetary A index was 31 (STAR Ap - based on the mean of three hour interval ap indices: 30.6). Three hour interval K indices: 54433355 (planetary), 45543343 (Boulder), 55544454 (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 12 active regions using 2K resolution (SN: 257) and in 11 active regions using 1K resolution (SN: 176) SDO/HMI images.

AR 14105 [S15W46] lost area and spots. A small magnetic delta configuration developed in the trailing part of the leading spot section. A minor M flare is possible. C1 flares: C1.9 @ 00:30, C1.4 @ 13:32, C1.4 @ 19:11 UT
AR 14109 [S17W26] decayed losing the leader spots.
AR 14110 [N06W30] developed as new flux emerged. The region has minor polarity intermixing.
AR 14111 [N14E28] was quiet and stable.
AR 14112 [S08E09] was quiet and stable.
AR 14113 [N10E47] was quiet and stable.
AR 14114 [N18E51] developed slowly and was mostly quiet.
New AR 14115 [N20E65] rotated into view on June 11 and was numbered by SWPC the next day. C1 flares: C1.0 @ 14:58, C1.0 @ 17:02 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S11145 [S15W66] decayed losing the magnetic delta configuration. The region was mostly quiet, however, there is still a chance of a minor M class flare. C1 flares: C1.2 @ 05:33, C1.7 @ 12:11, C1.7 @ 12:47, C1.1 @ 14:47 UT
S11148 [N20W10] was quiet and stable.
New region S11157 [S11E54] emerged with tiny spots.
New region S11158 [S07E30] emerged with a tiny spot.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.9 02:01   14105 GOES18  
C2.0 02:31   S11145 GOES18  
C2.4 02:41   14105 GOES18  
C2.4 02:49   14105 GOES18  
C2.0 03:04   S11145 GOES18  
C2.8 10:58   14105 GOES18  
C2.8 11:13   S11145 GOES18  
C2.6 11:32   14105 GOES18  
C5.8/1F 17:48 N21E74 14115 GOES18  
C2.6 20:20   14115 GOES18 LDE
C2.1 21:37   14105 GOES18  
C3.9 23:45 S14W48 14105 GOES18 LDE

Coronal mass ejections (CMEs)

June 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 large recurrent positive polarity southern hemisphere coronal hole (CH1301) will be Earth facing on June 11-19.

Forecast

The geomagnetic field is expected to be at unsettled to severe storm levels on June 13 due to CIR effects associated with CH1301. Quiet to minor storm levels will be possible on June 14-21 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 42 22 S15W46 0260 EKC EAC

was AR S11119

area: 0340

S11120 2025.06.02       N12W47          
14107 2025.06.05
2025.06.06
3     S15W67 0220 DAO       was AR S11129

location: S19W69

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
  5 2 S17W32 0010   AXX was AR S11131

location: S17W26

14108 2025.06.06
2025.06.07
      S21W85         was AR S11133

location: S20W88

S11138 2025.06.07       S03W29            
14111 2025.06.08
2025.06.09
1 9 2 N15E27 0120 HSX HAX was AR S11139

area: 0190

loction: N14E28

14110 2025.06.08
2025.06.09
5 31 14 N06W30 0030 DAO DAI beta-gamma

was AR S11140

area: 0110

14112 2025.06.08 1 14 5 S06E11 0005 AXX CRO was AR S11141

area: 0030

location: S08E09

S11142 2025.06.08       S24W44            
S11143 2025.06.08       S22W22            
S11145 2025.06.09   9 6 S15W66 0320   DKC

this became AR 14107 to SWPC on 2025.06.10

S11146 2025.06.09       N03W39            
S11147 2025.06.09       S27W52            
S11148 2025.06.10   1 1 N20W10 0003   AXX  
14113 2025.06.10
2025.06.11
2 3 1 N10E50 0020 HSX CSO was AR S11149

location: N10E47

area: 0050

14114 2025.06.10
2025.06.11
5 15 7 N18E57 0070 CAI DAI beta-gamma

was AR S11150

area: 0100

location: N18E51

SWPC location is way off

14115 2025.06.11
2025.06.12
4 5 4 N21E67 0180 DSO ESO was AR S11151

location: N20E65

area: 0260

S11152 2025.06.11       N15W00          
S11153 2025.06.11       S34W08          
S11154 2025.06.11       S32W26          
S11155 2025.06.11       N04E05          
S11156 2025.06.11       S16W54          
S11157 2025.06.12   2 2 S11E54 0005   BXO    
S11158 2025.06.12   1   S07E30 0004   AXX    
Total spot count: 36 137 66  
Sunspot number: 116 257 176  (total spot count + 10 * number of spotted regions)
Weighted SN: 76 180 109  (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): 128 141 141  

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
2025.06 131.4 (1)   39.4 (2A) / 98.6 (2B) / 120.7 (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.