Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 9, 2026 at 17:05 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, 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. No CME impact from the June 6 event was recorded until 09:51 UT on June 9. Solar wind speed at SOHO ranged between 433 and 556 km/sec, averaging 472 km/sec (-72 km/sec compared to the previous day). The high latitude magnetometer at Andenes was at unsettled to active levels. The above 10 MeV proton flux decreased towards background levels.

Solar flux density measured at 20h UT on 2.8 GHz was 130.7 - increasing 19.5 over the previous solar rotation.

The 365 day average solar flux at 1 AU was 140.29 (183 days ago). The 81 day average solar flux at 1 AU was 128.2 (41 days ago, this is 37.4% 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: 7.1). Three hour interval K indices: 12223112 (planetary), 13323312 (Boulder), 43344344 (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 12 active regions using 2K resolution (SN: 240) and in 10 active regions using 1K resolution (SN: 151) SDO/HMI images.

AR 14458 [S06W74] decayed slowly and was mostly quiet. C1 flares: C1.3 @ 08:29 UT
AR 14459 [N15W26] decayed slowly and quietly.
AR 14461 [S19W08] decayed slowly and could soon become spotless.
AR 14462 [S15W09] decayed slowly and was mostly quiet. C1 flares: C1.5 @ 06:38 UT
AR 14463 [N17E25] was quiet and stable.
AR 14464 [S11E23] did not see major changes and was mostly quiet. C1 flares: C1.3 @ 17:33 UT
New AR 14465 [N08E71] rotated into view on June 7 and was numbered by SWPC the next day. The region could have M class flare potential. C1 flares: C1.0 @ 01:07, C1.3 @ 03:50, C1.6 @ 04:21, C1.2 @ 04:43, C1.1 @ 06:50, C1.2 @ 07:40, C1.0 @ 10:20, C1.0 @ 11:01 UT

Spotted regions not observed (or interpreted differently) by SWPC/USAF:
AR S12114 [N25W35] was quiet and stable.
AR S12116 [N18W61] decayed further and was mostly quiet. C1 flares: C1.5 @ 12:41, C1.0 @ 16:24, C1.0 @ 16:52, C1.0 @ 23:37 UT
AR S12119 [N20W17] was quiet and stable.
AR S12122 [N07W02] was quiet and stable.
AR S12124 [S06W16] decayed slowly and quietly.

AR 14455 at the northwest limb produced a C1.1 flare at 11:13 UT

C2+ flares

Magnitude Peak time (UT) Location Source Recorded by Comment
C3.1 02:28   14465 GOES18  
C7.2 02:49   14465 GOES18  
C2.6 03:15   14465 GOES18  
C4.5 05:10 N10E81 14465 GOES18  

Coronal mass ejections (CMEs)

June 7-8: No obviously Earth directed CMEs were observed in available coronagraph imagery.
June 6: A full halo CME was observed after the M1 long duration event in AR 14461. The CME reached Earth on June 9.

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) will rotate into an Earth facing position on June 9-10.

Forecast

The geomagnetic field is expected to be at quiet to active levels on June 9 due to weak CME effects. A quiet field is likely on June 10-11 with unsettled to minor storm conditions likely on June 12-13 due to effects from CH1373.

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
14455 2026.05.26
2026.05.27
1     N15W90 0110 HSX    

was AR S12101

rotated out of view

14456 2026.05.29
2026.05.30
10     N17W61 0080 DAI       was AR S12105

real location: N15W67

spotless

SWPC relocated AR 14456 to AR S12116 on 2026.06.05

SWPC location on 2026.06.04: N14W13

14458 2026.05.30
2026.06.01
2 4 3 S05W76 0100 DAO DAO

was AR S12108

area: 0120

location: S06W74

14459 2026.05.31
2026.06.01
2 3 3 N14W29 0030 HSX CSO

was AR S12110

area: 0060

location: N15W26

14461 2026.06.01   4   S21W09 0005   BXO was AR S12112

area: 0020

location: S19W08

S12113 2026.06.01       S24W57            
S12114 2026.06.02   5 2 N25W35 0008   BXO  
14462 2026.06.02
2026.06.02
10 27 12 N15W07 0060 DSI DAI

was AR S12115

area: 0120

S12116 2026.06.04   20 8 N18W61 0110   EAI

see AR 14456

14463 2026.06.04
2026.06.05
1 6 1 N17E24 0040 HSX CSO was AR S12117

area: 0120

location: N17E25

S12119 2026.06.04   2 1 N20W17 0005   AXX  
14464 2026.06.04
2026.06.06
9 28 14 S12E24 0080 DAC DAI was AR S12120

area: 0350

location: S11E23

S12121 2026.06.06       N18E20            
S12122 2026.06.06   6 2 N07W02 0010   BXO  
S12123 2026.06.06       S10W60            
S12124 2026.06.07   2   S06W16 0002   BXO  
14465 2026.06.07
2026.06.08
4 13 5 N11E71 0070 DAO DKI was AR S12125

area: 0380

location: N08E71

S12126 2026.06.07       N07W53          
Total spot count: 39 120 51  
Sunspot number: 119 240 151  (total spot count + 10 * number of spotted regions)
Weighted SN: 79 160 91  (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): 131 132 121  

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
2026.06 139.5 (1)   37.1 (2A) / 139.3 (2B) / 119.7 (2C) (86.6 projected, -2.1) (12.0)
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.