Solar flares on September 18, 2025
The most powerful solar flare in 24 hours
C3.6 (normal) flare - September 18 at 1:11 PM
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-02:30 (Saint john's) — 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 | 19:58 | 20:11 | 20:26 | 4223 |
| C2.0 | 19:33 | 19:40 | 19:43 | 4220 |
| C1.4 | 18:38 | 18:44 | 18:48 | 4220 |
| C3.6 | 13:04 | 13:11 | 13:16 | 4220 |
| C1.8 | 12:09 | 12:17 | 12:27 | 4020 |