Solar flares on September 18, 2025
The most powerful solar flare in 24 hours
C3.6 (normal) flare - September 18 at 9:41 AM
Solar activity index
Value as of the end of the day on September 18, 2025
Solar X-ray emission over the past 2 days
Chart of solar X-ray emission (1-8 Å) from September 17, 2025 to September 18, 2025
Time zone — UTC-06 (Calgary) — summer time
List of solar flares for September 18, 2025
The total number of solar flares of class C and higher — 5 flares
C class — 5 | M class — 0 | X class — 0
| Class | begin | max | end | region |
|---|---|---|---|---|
| C2.9 | 16:28 | 16:41 | 16:56 | 4223 |
| C2.0 | 16:03 | 16:10 | 16:13 | 4220 |
| C1.4 | 15:08 | 15:14 | 15:18 | 4220 |
| C3.6 | 09:34 | 09:41 | 09:46 | 4220 |
| C1.8 | 08:39 | 08:47 | 08:57 | 4020 |