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Solar flares in October 2021
C-class73
M-class7
X-class0
LargestM9.92021-10-28
Sunspot number36.6NOAA SWPC
Flares per day (C and above)
M/X flares per day
Same month a year earlier
| Month | C | M | X | Largest |
|---|---|---|---|---|
| October 2020 | 14 | 0 | 0 | C4.3 |
| October 2021 | 73 | 7 | 0 | M9.9 |
Top 15 flares
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 2021-10-28 | 15:17 | 15:35 | 30 | M9.9 | – | – |
| 2021-10-28 | 10:19 | 10:28 | 17 | M2.2 | – | – |
| 2021-10-09 | 06:19 | 06:38 | 33 | M1.6 | – | – |
| 2021-10-29 | 02:22 | 02:42 | 30 | M1.5 | – | – |
| 2021-10-28 | 07:30 | 07:40 | 14 | M1.4 | – | – |
| 2021-10-26 | 02:40 | 02:47 | 13 | M1.3 | – | – |
| 2021-10-26 | 15:42 | 15:57 | 19 | M1.0 | – | – |
| 2021-10-26 | 00:48 | 01:04 | 24 | C9.3 | – | – |
| 2021-10-25 | 19:47 | 19:56 | 13 | C8.5 | – | – |
| 2021-10-27 | 05:47 | 06:08 | 31 | C8.5 | – | – |
| 2021-10-26 | 05:56 | 06:04 | 13 | C7.8 | – | – |
| 2021-10-29 | 06:00 | 06:07 | 14 | C5.9 | – | – |
| 2021-10-07 | 02:35 | 02:46 | 18 | C5.5 | – | – |
| 2021-10-26 | 09:43 | 09:52 | 18 | C5.0 | – | – |
| 2021-10-26 | 11:11 | 11:25 | 18 | C4.9 | – | – |
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.
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About this page
80 flares of class C or larger in October 2021; by M/X count it ranks 289 of 565 months.