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Solar flares in September 2011
C-class152
M-class31
X-class4
LargestX2.12011-09-06
Sunspot number106.4NOAA SWPC
Flares per day (C and above)
M/X flares per day
Same month a year earlier
| Month | C | M | X | Largest |
|---|---|---|---|---|
| September 2010 | 9 | 0 | 0 | C3.3 |
| September 2011 | 152 | 31 | 4 | X2.1 |
Top 15 flares
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 2011-09-06 | 22:12 | 22:20 | 12 | X2.1 | – | 11283 |
| 2011-09-24 | 09:21 | 09:40 | 27 | X1.9 | – | 11302 |
| 2011-09-07 | 22:32 | 22:38 | 12 | X1.8 | – | 11283 |
| 2011-09-22 | 10:29 | 11:01 | 75 | X1.4 | – | 11302 |
| 2011-09-25 | 04:31 | 04:50 | 34 | M7.4 | – | 11302 |
| 2011-09-24 | 12:33 | 13:20 | 97 | M7.1 | – | 11302 |
| 2011-09-08 | 15:32 | 15:46 | 20 | M6.7 | – | 11283 |
| 2011-09-24 | 20:29 | 20:36 | 13 | M5.8 | – | 11302 |
| 2011-09-06 | 01:35 | 01:50 | 30 | M5.3 | – | 11283 |
| 2011-09-25 | 02:27 | 02:33 | 10 | M4.4 | – | 11302 |
| 2011-09-26 | 05:06 | 05:08 | 7 | M4.0 | – | 11302 |
| 2011-09-25 | 15:26 | 15:33 | 12 | M3.7 | – | 11302 |
| 2011-09-04 | 11:21 | 11:45 | 29 | M3.2 | – | 11286 |
| 2011-09-24 | 17:19 | 17:25 | 12 | M3.1 | – | 11302 |
| 2011-09-25 | 08:46 | 08:49 | 6 | M3.1 | – | 11302 |
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
187 flares of class C or larger in September 2011; by M/X count it ranks 90 of 565 months.