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Solar flares in May 1991
C-class206
M-class39
X-class2
LargestX2.81991-05-18
Flares per day (C and above)
M/X flares per day
Same month a year earlier
| Month | C | M | X | Largest |
|---|---|---|---|---|
| May 1990 | 151 | 28 | 8 | X9.3 |
| May 1991 | 206 | 39 | 2 | X2.8 |
Top 15 flares
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 1991-05-18 | 05:06 | 05:46 | 162 | X2.8 | N32W85 | 6619 |
| 1991-05-29 | 22:14 | 23:43 | 149 | X1.0 | N05E38 | 6654 |
| 1991-05-16 | 06:35 | 06:54 | 175 | M8.9 | N30W56 | 6619 |
| 1991-05-13 | 01:03 | 01:44 | 79 | M8.2 | – | – |
| 1991-05-30 | 09:43 | 09:44 | 24 | M8.2 | N07E30 | 6654 |
| 1991-05-28 | 10:18 | 10:23 | 13 | M5.3 | N08E57 | 6654 |
| 1991-05-29 | 12:07 | 12:10 | 24 | M4.3 | N08E43 | 6654 |
| 1991-05-31 | 03:44 | 03:45 | 46 | M3.8 | N09E15 | – |
| 1991-05-11 | 13:21 | 13:22 | 23 | M3.4 | S08W80 | 6615 |
| 1991-05-17 | 09:03 | 09:04 | 76 | M3.3 | N29W73 | 6619 |
| 1991-05-28 | 07:00 | 07:01 | 77 | M3.2 | N06E61 | 6654 |
| 1991-05-29 | 16:29 | 16:29 | 80 | M2.7 | S08E35 | 6652 |
| 1991-05-31 | 16:19 | 16:56 | 109 | M2.5 | S08E09 | 6652 |
| 1991-05-28 | 13:05 | 13:13 | 25 | M2.4 | N08E55 | 6654 |
| 1991-05-07 | 00:01 | 00:34 | 113 | M2.3 | S07W22 | 6615 |
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
247 flares of class C or larger in May 1991; by M/X count it ranks 61 of 565 months.