Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 16, 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 unsettled levels on June 15, weakly under the influence of effects from CH1301. Solar wind speed at SOHO ranged between 426 and 607 km/sec, averaging 495 km/sec (+10 km/sec compared to the previous day). The high latitude magnetometer at Andenes recorded quiet to active 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 160.5 - increasing 43.7 over the previous solar rotation. The 365 day average solar flux at 1 AU was 187.98 (183 days ago). SC25 365d peak: 195.86 on October 13, 2024. The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 9.3). Three hour interval K indices: 21222332 (planetary), 21233322 (Boulder), 42333433 (Andenes).

The background x-ray flux is at the class C2 level (GOES 19).

At the time of counting spots (see image time), spots were observed in 11 active regions using 2K resolution (SN: 265) and in 11 active regions using 1K resolution (SN: 194) SDO/HMI images.

AR 14105 [S16W78] decayed further and rotated mostly out of view while producing several C and M flares. C1 flares: C1.9 @ 09:44 UT
AR 14110 [N05W73] decayed slowly and was mostly quiet.
AR 14111 [N14W12] gained tiny spots and has polarity intermixing.
AR 14112 [S09W31] decayed slowly and quietly and could soon become spotless.
AR 14113 [N10E06] was quiet and stable.
AR 14114 [N18E14] developed further and has multiple magnetic delta configurations. Further major M or X flares are possible. C1 flares: C1.9 @ 02:52 UT
AR 14115 [N20E22] was mostly quiet and stable.
AR 14116 [S11E12] matured and was mostly quiet.

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
S11159 [S02E21] reemerged with tiny spots.
S11160 [S14W00] was quiet and stable.
New region S11163 [N22E21] emerged just north of AR 14115 with tiny spots.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.0 00:54   14110 GOES18  
C2.7 01:16   14105 GOES18  
C2.7 01:45   14110 GOES18  
C2.7 01:58   14105 GOES18  
C7.5 03:29 N17E24 14114 GOES18 partial halo CME
C5.1 04:03   14114 GOES18  
C6.5 04:35   14114 GOES18 simultaneous flare in AR 14105
C3.2 05:24   14114 GOES18  
C3.0 06:19   14111 GOES18  
C2.9 06:49   14114 GOES18  
M2.2/1N 07:56 S14W67 14105 GOES18 CME, moderate type II radio sweep
C2.4 10:11   14110 GOES18  
M1.9 10:47   14105 GOES18  
C3.0 12:11 S12W84 (SDO/AIA) S11161 GOES18  
C2.9 12:55 S14W70 14105 GOES18  
C3.3 13:12   14114 GOES18  
C5.0 13:16   14105 GOES18  
C2.6 13:32   S11161 GOES18  
C2.8 13:43   14105 GOES18  
C3.1 14:17 N18E20 14114 GOES18  
C2.0 14:53   S11161 GOES18  
C2.6 16:55   14105 GOES18  
C4.5 17:09 N18E19 14114 GOES18  
C4.7 17:19   14105 GOES18  
C4.7 17:26   14114 GOES18  
M8.4/1B 18:06 N18E16 14114 GOES18 partial halo CME, strong type II and weak type IV radio sweeps
C7.9 19:31   14114 GOES18  
C9.8 19:50   14114 GOES18  
C7.9 20:38   14114 GOES18  
C4.3 21:34   14105 GOES18  
C3.8 21:56   S11161 GOES18  
C4.4 22:31 N18E15 14114 GOES18  
C7.2 22:40   S11161 GOES18  
C5.0 22:50   14114 GOES18  
C4.5 23:10   14114 GOES18  
C4.3 23:19   14114 GOES18  
M1.2 23:57 N18E17 14114 GOES18  

Coronal mass ejections (CMEs)

June 13-14: No obviously Earth directed CMEs.
June 15: AR 14114 produced 2 CMEs that may have had Earth directed components. The first one was associated with a C7.5 flare peaking at 03:29 and the last one was observed after the major M8 flare at 18:06 UT. Both CMEs were brightest off the north pole. The latter one was at least a partial halo CME with faint extensions off east and west limbs. Components from this CME could reach Earth sometime between late on June 17 and noon on June 18.

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

Forecast

The geomagnetic field is expected to be at quiet to minor storm levels on June 16-23 due to effects associated with CH1301. If the last of the 2 June CMEs reaches Earth, unsettled to major storm levels will be possible on June 17-18.

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
14105 2025.06.02
2025.06.03
9 4 1 S14W84 0240 DSO AXX

was AR S11119

area: 0007

location: S16W78

14109 2025.06.05
2025.06.07
2     S17W76 0020 CAO       was AR S11131

spotless

SWPC spots appear to be the trailing spots of AR 14105

14111 2025.06.08
2025.06.09
4 21 10 N15W14 0110 CSO CAO beta-gamma

was AR S11139

area: 0160

loction: N14W12

14110 2025.06.08
2025.06.09
8 21 10 N05W72 0180 DAI EAI

was AR S11140

location: N05W73

14112 2025.06.08   3 2 S09W33 0013   AXX was AR S11141

location: S09W31

S11148 2025.06.10       N20W49            
14113 2025.06.10
2025.06.11
1 4 3 N10E05 0030 HSX CSO was AR S11149

location: N10E06

area: 0080

14114 2025.06.10
2025.06.11
27 65 39 N17E12 0380 EKC EKC beta-gamma-delta

was AR S11150

area: 0760

location: N18E14

14115 2025.06.11
2025.06.12
4 9 3 N21E26 0150 ESO ESO was AR S11151

location: N20E22

area: 0180

S11152 2025.06.11       N15W39            
S11153 2025.06.11       S34W47            
S11155 2025.06.11       N04W34            
14116 2025.06.12
2025.06.14
6 14 8 S11E12 0140 DSO DAO was AR S11157

location: S11E25

area: 0230

S11158 2025.06.12       S07W09            
S11159 2025.06.13   4 3 S02E21 0010   BXO    
S11160 2025.06.14   5 1 S14W00 0010   BXO  
S11162 2025.06.14       N21E36          
S11163 2025.06.15   5 4 N22E21 0014   BXO    
Total spot count: 61 155 84  
Sunspot number: 141 265 194  (total spot count + 10 * number of spotted regions)
Weighted SN: 106 190 119  (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): 155 146 155  

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
2025.06 135.4 (1)   53.1 (2A) / 106.2 (2B) / 127.3 (2C) (114.4 projected, -4.9) (31.0)
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.