Solar Flare WatchHome › Flare history › 1991
X3.3 solar flare on 1991-09-07
ClassX3.3NOAA report
Peak19:351991-09-07 UTC
Duration70 min
Peak flux3.3e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 96 / 491 |
| Rank in year | 16 / 3297 |
| Other M/X flares that day | 4 |
| M/X flares that month | 26 |
| Solar cycle | Cycle 22 |
| Position on disk | S11W50 |
| Active region | AR 6818 (13 flares) |
Compared with the strongest flares of 1991
X12.0
X12.0
X12.0
X12.0
X12.0
X10.0
X10.0
X9.4
X7.1
X6.1
X5.5
X5.3
Other M/X flares that day
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 06:29 | 07:57 | 133 | M2.1 | S13W45 | 6818 | |
| 09:40 | 10:16 | 102 | M4.1 | S11W48 | 6818 | |
| 12:33 | 12:48 | 74 | M2.1 | S11W46 | 6818 | |
| 18:21 | 18:51 | 38 | M1.9 | S11W51 | 6818 |
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.
← X2.1 1991-08-25X1.0 1991-09-08 →
About this page
A X3.3 flare that began 1991-09-07 19:11 UTC; No. 16 of 3,297 C-class-or-larger flares in 1991.