Solar flares on September 28, 2025
The most powerful solar flare in 24 hours
M6.4 (strong) flare - September 28 at 4:43 AM
Solar activity index
Value as of the end of the day on September 28, 2025
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from September 27, 2025 to September 28, 2025
Time zone — UTC-04 (Concord) — summer time
List of solar flares for September 28, 2025
The total number of solar flares of class C and higher — 20 flares
C class — 18 | M class — 2 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C4.4 | 23:49 | 23:58 | 00:11 | 4227 |
| C2.9 | 23:14 | 23:21 | 23:24 | 4236 |
| M3.6 | 21:37 | 21:45 | 21:47 | 4232 |
| C5.8 | 19:41 | 19:46 | 19:48 | 4233 |
| C6.3 | 19:24 | 19:35 | 19:41 | 4233 |
| C3.3 | 18:10 | 18:17 | 18:21 | — |
| C5.5 | 17:43 | 17:50 | 17:56 | 4235 |
| C9.6 | 16:17 | 16:34 | 16:51 | 4233 |
| C7.4 | 15:37 | 15:56 | 16:01 | 4232 |
| C2.9 | 15:12 | 15:21 | 15:27 | 4236 |
| C3.7 | 13:35 | 13:42 | 13:46 | 4232 |
| C3.5 | 12:38 | 12:46 | 12:50 | — |
| C3.6 | 10:35 | 10:40 | 10:48 | 4233 |
| C9.9 | 09:26 | 09:31 | 09:34 | 4233 |
| C9.0 | 09:12 | 09:24 | 09:26 | 4233 |
| C3.2 | 08:46 | 08:55 | 09:03 | 4233 |
| C3.6 | 07:29 | 07:42 | 07:55 | 4233 |
| C3.0 | 06:48 | 06:54 | 06:56 | 4232 |
| M6.4 | 04:34 | 04:43 | 04:49 | 4232 |
| C2.3 | 03:02 | 03:07 | 03:25 | 4233 |