The geomagnetic field was at quiet to unsettled levels on June 24. A weak disturbance began after 06h UT and peaked after noon. As the phi angle moved into a negative sector at the time, the most likely source of the disturbance were weak effects associated with CH1303. Solar wind speed at SOHO ranged between 378 and 485 km/sec, averaging 431 km/sec (-2 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 119.9 - decreasing 24.4 over the previous solar rotation. The 365 day average solar flux at 1 AU was 186.43 (183 days ago). The 81 day average solar flux at 1 AU was 145.5 (41 days ago, this is 48.3% of the 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: 195.86 on October 13, 2024. The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 6.9). Three hour interval K indices: 12222321 (planetary), 12332322 (Boulder), 12214232 (Andenes).
The background x-ray flux is at the class B4 level (GOES 19).
At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 197) and in 8 active regions using 1K resolution (SN: 131) SDO/HMI images.
AR 14117 [S15W16] decayed slowly and produced a
few low level C flares. C1 flares: C1.1 @ 00:28, C1.3 @ 04:55, C1.1 @ 15:06
UT
AR 14118 [S12W03] decayed further and was the source of a few low
level C flares. C1 flares: C1.1 @ 05:28, C1.5 @ 17:27, C1.8 @ 17:58, C1.1 @
20:51 UT
AR 14119 [S25W14] decayed slowly and quietly.
AR 14120 [N06W09] developed quickly after noon as new flux emerged.
AR 14121 [S12E13] developed slowly and quietly.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S11182 [S12W20] decayed slowly and quietly.
S11186 [S21W09] decayed slowly and quietly.
S11187 [N14E39] was quiet and stable.
S11188 [N14E72] gained spots and was mostly quiet. Two of the
opposite polarity spots are very close to each other. C1 flares: C1.1 @
12:27, C1.1 @ 13:57, C1.3 @ 14:47 UT
New region S11190 [N04E21] was observed with tiny spots in an
old plage area.
AR 14114 behind the northwest limb produced a C1.0 flare at 03:43 UT.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C3.1 | 15:45 | 14117 | GOES18 |
June 22-24: No obviously Earth directed CMEs.
[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 small recurrent negative polarity trans equatorial coronal hole (CH1303) was Earth facing on June 20 and early on June 21. A large recurrent negative polarity trans equatorial coronal hole (CH1302) will rotate across the central meridian on June 22-25.
The geomagnetic field is expected to be at quiet to minor storm levels on June 25-28 due to effects from CH1302.
| 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.
(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 | ||||||||||
| 14115 | 2025.06.11 2025.06.12 |
1 | N21W95 | 0030 | HSX |
was AR S11151 spotless for 2 consecutive days location: N22W84 |
|||||
| S11162 | 2025.06.14 | N26W52 | |||||||||
| S11166 | 2025.06.16 | S12W57 | |||||||||
| 14117 | 2025.06.17 2025.06.18 |
6 | 14 | 8 | S14W17 | 0150 | DSO | DAO |
 |
 |
was AR S11167 location: S15W16 area: 0240 |
| S11169 | 2025.06.17 | S09W56 | |||||||||
| 14118 | 2025.06.17 2025.06.19 |
10 | 26 | 16 | S12W07 | 0080 | CAI | DAI |
 |
 |
beta-gamma was AR S11170 location: S12W03 area: 0170 leader spots split off into AR S11182 on 2025.06.22 |
| S11173 | 2025.06.18 | N14W42 |
 |
||||||||
| S11175 | 2025.06.19 | N08W53 | |||||||||
| S11177 | 2025.06.19 | N13W30 | |||||||||
| 14119 | 2025.06.21 2025.06.23 |
2 | 3 | 1 | S25W16 | 0005 | AXX | CRO |
 |
 |
was AR S11179 location: S25W14 area: 0020 |
| S11181 | 2025.06.21 | S13W31 | |||||||||
| S11182 | 2025.06.22 | 3 | 3 | S12W20 | 0090 | CSO |
 |
 |
split off from AR 14118 | ||
| 14120 | 2025.06.22 2025.06.23 |
5 | 17 | 11 | N06W10 | 0010 | BXO | DRI |
 |
 |
was AR S11183 location: N06W09 area: 0100 |
| 14121 | 2025.06.22 2025.06.23 |
3 | 15 | 6 | S12E11 | 0030 | DRO | DRO |
 |
 |
was AR S11184 area: 0080 location: S12E13 |
| S11186 | 2025.06.23 | 3 | S21W09 | 0005 | AXX |
 |
 |
||||
| S11187 | 2025.06.23 | 5 | 2 | N14E39 | 0015 | BXO |
 |
 |
|||
| S11188 | 2025.06.23 | 9 | 4 | N14E72 | 0025 | BXI |
 |
 |
beta-gamma | ||
| S11190 | 2025.06.24 | 2 | N04E21 | 0004 | BXO |
 |
|||||
| Total spot count: | 27 | 97 | 51 | ||||||||
| Sunspot number: | 87 | 197 | 131 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 45 | 118 | 72 | (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): | 96 | 108 | 105 | ||||||||
| 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 | 133.7 (1) | 83.4 (2A) / 104.3(2B) / 124.9 (2C) ISN average to date: 110.6. At this level the SSN for December 2024 will become 150.9 |
(114.4 projected, -4.9) | (22.8) | |
| 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
Sunspot activity has been on a decreasing trend since September
2024 (using the average solar flux over 3 solar rotations as a proxy).
Compared to the peak of SC25 solar flux has been at a low level in both May
and June 2025. Taking a closer look at the 81 day (3 solar rotations)
average solar flux proxy, its peak was in early September 2024 and had on
May 12 decreased to less than half of the solar cycle flux range.
Subtracting the 81 day average of approximately 69 at solar cycle minimum
from all measurements, the SC25 range is 0 - 158.3.
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.
--------------------------------------------------------------------------------------
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.
