Solar flares on September 17, 2025
The most powerful solar flare in 24 hours
C2.8 (normal) flare - September 17 at 5:04 PM
Solar activity index
Value as of the end of the day on September 17, 2025
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from September 16, 2025 to September 17, 2025
Time zone — UTC-07 (Seattle) — summer time
List of solar flares for September 17, 2025
The total number of solar flares of class C and higher — 6 flares
C class — 6 | M class — 0 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C1.7 | 18:34 | 18:38 | 18:40 | 4220 |
| C2.8 | 16:55 | 17:04 | 17:13 | 4217 |
| C1.6 | 15:42 | 15:47 | 15:51 | 4220 |
| C1.4 | 15:32 | 15:38 | 15:42 | 4220 |
| C2.3 | 08:35 | 08:41 | 08:43 | 4216 |
| C1.7 | 05:13 | 05:19 | 05:21 | 4216 |