Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 11, 2026 at 02:40 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, 2026)
Solar cycle Solar cycles 23-25 (June 1, 2026) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24-25 progress (June 1, 2026) 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, 2026) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12-14, 16, 24-25 (June 1, 2026) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (December 21, 2025) Cycle 25 initial spots (final update December 25, 2019)
  Solar cycles 24-25 transition using 365d smoothing  

Recent activity

The geomagnetic field was at quiet to unsettled levels. Solar wind speed at SOHO ranged between 368 and 454 km/sec, averaging 392 km/sec (-46 km/sec compared to the previous day). The high latitude magnetometer at Andenes was at 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 124.0 - increasing 17.6 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 140.30 (183 days ago). The 81 day average solar flux at 1 AU was 128.9 (41 days ago, this is 37.8% of the total 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: 195.9 on October 13, 2024.

The Potsdam WDC planetary A index was 7 (STAR Ap - based on the average of three hour interval ap indices: 6.8). Three hour interval K indices: 21133211 (planetary), 21133222 (Boulder), 31134323 (Andenes).

The background x-ray flux is at the class B6 level (GOES 19).

At the time of counting spots (see image time), spots were observed in 11 active regions using 2K resolution (SN: 212) and in 8 active regions using 1K resolution (SN: 129) SDO/HMI images.

AR 14459 [N15W53] decayed slowly and quietly.
AR 14461 [S22W33] was quiet and stable.
AR 14462 [N15W35] decayed slowly and quietly.
AR 14463 [N17W01] was quiet and stable.
AR 14464 [S12W05] decayed slowly and quietly.
AR 14465 [N08E44] lost the magnetic delta configuration, gained spots and was mostly quiet. Minor polarity intermixing was observed in the northern section. The region produced a long duration C6.7 event peaking at 00:02 on June 11 associated with a full halo CME. C1 flares: C1.1 @ 01:33, C1.1 @ 16:07 UT
New AR 14466 [N06W30] was mostly quiet and in slow decay. C1 flares: C1.1 @ 01:07, C1.0 @ 04:15, C1.0 @ 05:16 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S12131 [S04E54] was quiet and stable.
New AR S12133 [N11E11] emerged with tiny spots.
New AR S12134 [S12E81] rotated into view with a tiny spot.
New AR S12135 [S17E08] was observed with tiny spots in an old plage area.

AR S12116 produced a C1.5 flare at 13:25 and a C1.0 flare at 15:34 UT while at the northwest limb.

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C2.6 00:59   14465 GOES18  
C6.7 00:02 (on June 11)   14465 GOES18 LDE, CME
flare began at 23:14 UT

Coronal mass ejections (CMEs)

June 8-10: No obviously Earth directed CMEs were observed in available coronagraph imagery.
June 11: A full halo CME was observed early in the day following a C6.5 long duration event in AR 14465. The CME could reach Earth on June 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 recurrent negative polarity trans equatorial coronal hole (CH1373) was in an Earth facing position on June 9-10.

Forecast

The geomagnetic field is expected to be at quiet levels on June 11. Unsettled to minor storm conditions are likely on June 12-13 due to effects from CH1373. The June 11 CME could reach Earth on June 13 and cause active to major storm conditions that day and on June 14.

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
14456 2026.05.29
2026.05.30
3     N18W87 0060 ESO       was AR S12105

real location: N15W93

rotated out of view

SWPC relocated AR 14456 to AR S12116 on 2026.06.05

SWPC location on 2026.06.04: N14W13

SWPC copied the sunspot data from the previous day on June 10 instead of using observational data

14459 2026.05.31
2026.06.01
1 3 1 N14W56 0010 HRX BXO

was AR S12110

location: N15W53

14461 2026.06.01   3 1 S21W37 0005   BXO was AR S12112

location: S22W33

14462 2026.06.02
2026.06.02
10 11 6 N16W35 0040 DSI DAO

was AR S12115

location: N15W35

14463 2026.06.04
2026.06.05
1 7 4 N16W04 0070 HSX CSO was AR S12117

area: 0110

location: N17W01

S12119 2026.06.04       N20W38          
14464 2026.06.04
2026.06.06
15 31 15 S12W03 0180 DSI DSI was AR S12120

area: 0210

location: S12E09

S12121 2026.06.06       N18W06            
14466 2026.06.06
2026.06.09
4 13 6 N06W31 0015 DAO DRO was AR S12122

area: 0050

location: N06W30

S12124 2026.06.07       S06W42            
14465 2026.06.07
2026.06.08
10 26 15 N09E40 0240 DSI DAI beta-gamma

was AR S12125

area: 0330

location: N08E44

S12127 2026.06.09       S07W07          
S12128 2026.06.09       S43W15          
S12129 2026.06.09       N05W07          
S12130 2026.06.09       N32W24          
S12131 2026.06.09   3   S04E54 0003   AXX  
S12133 2026.06.10   2 1 N11E11 0005   AXX    
S12134 2026.06.10   1   S12E81 0001   AXX    
S12135 2026.06.10   2   S17E08 0004   AXX    
Total spot count: 44 102 49  
Sunspot number: 114 212 129  (total spot count + 10 * number of spotted regions)
Weighted SN: 77 125 82  (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): 125 117 103  

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2024.05 187.7 191.9 172.1 149.1 (+4.6) 23.56
(SC25 peak)
2024.08  246.1
(SC25 peak)
252.2 216.0  (SC25 peak) 156.8 (+1.8) 15.96
2024.10 221.0 219.6 165.8 160.9 (+1.5) (SC25 solar max) 18.99
2025.03 163.7 162.1 134.2 135.9 (-3.9) 15.96
2025.04 162.5 163.6 141.4 133.3 (-2.6) 17.62
2025.05 135.3 138.3 78.5 128.6 (-4.7) 17.26
2025.06 131.3 135.4 114.6 124.7 (-3.9) 21.43
2025.07 137.8 142.3 125.9 122.4 (-2.3) 11.80
2025.08 154.9 158.7 133.7 118.2 (-4.2) 9.97
2025.09 154.4 156.0 129.7 112.9 (-5.3) 14.02
2025.10 139.5 138.6 114.6 108.3 (-4.6) 15.64
2025.11 140.3 137.3 91.7 106.7 (-1.6) 21.01
2025.12 160.8 155.8 124.0 (106.4 projected, -0.3) 13.35
2026.01 148.7 144.0 112.6 (102.7 projected, -3.7) 22.47
2026.02 136.4 133.1 78.2 (98.5 projected, -4.2) 12.88
2026.03 131.0 129.7 85.9 (93.9 projected, -4.6) 15.44
2026.04  120.0 120.9 79.3 (90.0 projected, -3.9) 12.10
2026.05 125.4 128.2 101.4 (88.7 projected, -1.3) 9.8
2026.06 137.0 (1)   44.6 (2A) / 133.8 (2B) / 122.0 (2C) (86.6 projected, -2.1) (11.4)
2026.07       (82.2 projected, -4.4)  
2026.08       (80.1 projected, -2.1)  
2026.09       (79.1 projected, -1.0)  
2026.10       (77.1 projected, -2.0)  
2026.11       (74.3 projected, -2.8)  

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 March 2026

Solar activity appears to have exited the solar max phase as of February 2026 with a strong decrease in the number of sunspots observed. The northern polar field has weakened considerably over the last months, and although there is a chance the the field could recover over the next 1-2 years, there is an increasing chance that solar cycle 26 will be very weak. The southern polar field is not impressive either, however, a southern polar coronal hole has formed early in 2026 and appears to be growing.

All 365 day smoothed sunspot numbers reached a maximum on October 11-12, 2024
. This became the peak of SC25 (365 day smoothed peaks: STAR 1K: 236.1, STAR 2K: 364.3, NOAA SN: 156.0, ISN: 163.9), while 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.