Solar Flare WatchHome › Flare history › 2023
Solar flares in September 2023
C-class244
M-class34
X-class0
LargestM8.72023-09-21
Sunspot number129.9NOAA SWPC
Flares per day (C and above)
M/X flares per day
Same month a year earlier
| Month | C | M | X | Largest |
|---|---|---|---|---|
| September 2022 | 291 | 14 | 0 | M7.9 |
| September 2023 | 244 | 34 | 0 | M8.7 |
Top 15 flares
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 2023-09-21 | 12:42 | 12:54 | 19 | M8.7 | – | – |
| 2023-09-20 | 14:11 | 14:19 | 13 | M8.2 | – | – |
| 2023-09-03 | 08:09 | 08:36 | 39 | M6.0 | – | – |
| 2023-09-24 | 03:17 | 03:28 | 18 | M4.4 | – | – |
| 2023-09-19 | 20:01 | 20:14 | 19 | M4.0 | – | – |
| 2023-09-02 | 06:33 | 07:12 | 64 | M3.3 | – | – |
| 2023-09-16 | 00:38 | 00:50 | 18 | M2.9 | – | – |
| 2023-09-12 | 06:47 | 07:07 | 31 | M2.5 | – | – |
| 2023-09-14 | 21:17 | 21:26 | 14 | M2.5 | – | – |
| 2023-09-07 | 18:58 | 19:09 | 25 | M2.1 | – | – |
| 2023-09-05 | 08:03 | 08:12 | 20 | M2.0 | – | – |
| 2023-09-14 | 19:23 | 19:31 | 16 | M1.9 | – | – |
| 2023-09-22 | 22:25 | 23:00 | 47 | M1.9 | – | – |
| 2023-09-24 | 03:09 | 03:14 | – | M1.9 | – | – |
| 2023-09-19 | 09:23 | 09:38 | 20 | M1.8 | – | – |
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
278 flares of class C or larger in September 2023; by M/X count it ranks 93 of 565 months.