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Solar flares in May 2021
C-class38
M-class4
X-class0
LargestM3.92021-05-07
Sunspot number20.0NOAA SWPC
Flares per day (C and above)
M/X flares per day
Same month a year earlier
| Month | C | M | X | Largest |
|---|---|---|---|---|
| May 2020 | 2 | 1 | 0 | M1.1 |
| May 2021 | 38 | 4 | 0 | M3.9 |
Top 15 flares
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 2021-05-07 | 18:43 | 19:04 | 35 | M3.9 | – | – |
| 2021-05-22 | 21:30 | 21:36 | 12 | M1.4 | – | – |
| 2021-05-22 | 17:03 | 17:11 | 12 | M1.1 | – | – |
| 2021-05-23 | 11:00 | 11:08 | 13 | M1.1 | – | – |
| 2021-05-28 | 22:19 | 23:13 | 112 | C9.4 | – | – |
| 2021-05-08 | 18:22 | 18:45 | 35 | C8.6 | – | – |
| 2021-05-27 | 22:56 | 23:15 | 27 | C7.6 | – | – |
| 2021-05-22 | 23:05 | 23:13 | 11 | C6.8 | – | – |
| 2021-05-22 | 02:47 | 02:56 | 12 | C6.1 | – | – |
| 2021-05-22 | 06:06 | 06:17 | 17 | C6.0 | – | – |
| 2021-05-21 | 19:15 | 19:28 | 16 | C4.8 | – | – |
| 2021-05-09 | 13:38 | 13:58 | 30 | C4.0 | – | – |
| 2021-05-26 | 21:17 | 21:24 | – | C3.8 | – | – |
| 2021-05-26 | 21:34 | 21:38 | 7 | C3.4 | – | – |
| 2021-05-22 | 15:12 | 15:35 | 31 | C3.2 | – | – |
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.
About this page
42 flares of class C or larger in May 2021; by M/X count it ranks 340 of 565 months.