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Solar flares in May 1999
C-class161
M-class16
X-class0
LargestM7.61999-05-09
Sunspot number140.6NOAA SWPC
Flares per day (C and above)
M/X flares per day
Same month a year earlier
| Month | C | M | X | Largest |
|---|---|---|---|---|
| May 1998 | 141 | 15 | 2 | X2.7 |
| May 1999 | 161 | 16 | 0 | M7.6 |
Top 15 flares
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 1999-05-09 | 17:53 | 18:07 | 22 | M7.6 | – | 8537 |
| 1999-05-08 | 14:22 | 14:40 | 39 | M4.6 | N23W75 | 8526 |
| 1999-05-03 | 05:36 | 06:02 | 56 | M4.4 | N15E32 | – |
| 1999-05-07 | 04:28 | 04:41 | 21 | M3.2 | N20E87 | – |
| 1999-05-10 | 05:22 | 05:31 | 15 | M2.5 | N16E19 | 8539 |
| 1999-05-17 | 04:49 | 04:55 | 11 | M2.3 | – | – |
| 1999-05-03 | 23:07 | 23:11 | 6 | M1.9 | – | – |
| 1999-05-08 | 10:36 | 10:58 | 38 | M1.6 | N18E64 | – |
| 1999-05-29 | 03:04 | 03:15 | 23 | M1.6 | – | – |
| 1999-05-16 | 13:45 | 13:50 | 8 | M1.2 | S17W75 | 8534 |
| 1999-05-26 | 19:15 | 19:32 | 30 | M1.2 | N17E46 | – |
| 1999-05-09 | 00:36 | 00:47 | 22 | M1.1 | N21E69 | 8541 |
| 1999-05-16 | 17:20 | 17:25 | 8 | M1.1 | S17W76 | 8534 |
| 1999-05-09 | 11:52 | 12:27 | 56 | M1.0 | – | – |
| 1999-05-16 | 22:25 | 22:33 | 12 | M1.0 | – | 8541 |
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
177 flares of class C or larger in May 1999; by M/X count it ranks 183 of 565 months.