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Solar flares in September 2025
C-class174
M-class15
X-class0
LargestM3.62025-09-29
Sunspot number128.6NOAA SWPC
Flares per day (C and above)
M/X flares per day
Same month a year earlier
| Month | C | M | X | Largest |
|---|---|---|---|---|
| September 2024 | 149 | 55 | 2 | X4.4 |
| September 2025 | 174 | 15 | 0 | M3.6 |
Top 15 flares
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 2025-09-29 | 01:37 | 01:45 | 10 | M3.6 | – | – |
| 2025-09-30 | 12:02 | 12:27 | 46 | M1.7 | – | – |
| 2025-09-24 | 18:57 | 19:13 | 25 | M1.6 | – | – |
| 2025-09-26 | 19:49 | 20:01 | 18 | M1.6 | – | – |
| 2025-09-19 | 21:22 | 21:41 | 34 | M1.5 | – | – |
| 2025-09-05 | 01:08 | 01:16 | 13 | M1.4 | – | – |
| 2025-09-06 | 22:07 | 22:15 | 10 | M1.2 | – | – |
| 2025-09-27 | 04:18 | 04:23 | 9 | M1.1 | – | – |
| 2025-09-27 | 07:03 | 07:14 | 15 | M1.1 | – | – |
| 2025-09-29 | 11:23 | 11:39 | 29 | M1.1 | – | – |
| 2025-09-04 | 13:36 | 13:44 | 13 | M1.0 | – | – |
| 2025-09-23 | 10:24 | 10:34 | 14 | M1.0 | – | – |
| 2025-09-27 | 03:29 | 03:59 | – | M1.0 | – | – |
| 2025-09-29 | 11:06 | 11:15 | 12 | M1.0 | – | – |
| 2025-09-29 | 11:56 | 11:59 | 6 | M1.0 | – | – |
All times UTC. Until June 2017 classes are NOAA's reports of the time (GOES-15 and earlier included a 0.7 scaling factor); later classes come from calibrated GOES-16/18 data, so the same flare reads about 1.4× larger. Do not compare the two periods directly.
About this page
189 flares of class C or larger in September 2025; by M/X count it ranks 191 of 565 months.