Solar Flare WatchHome › Flare history › 1991
X2.3 solar flare on 1991-07-31
ClassX2.3NOAA report
Peak00:531991-07-31 UTC
Duration89 min
Peak flux2.3e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 169 / 491 |
| Rank in year | 21 / 3297 |
| Other M/X flares that day | 2 |
| M/X flares that month | 35 |
| Solar cycle | Cycle 22 |
| Position on disk | S17E11 |
| Active region | AR 6749 (9 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 |
|---|---|---|---|---|---|---|
| 08:17 | 08:20 | 15 | M1.0 | S05W55 | 6739 | |
| 22:48 | 22:51 | 26 | M1.7 | N23E31 | 6757 |
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.
← M7.2 1991-07-30X1.5 1991-08-02 →
About this page
A X2.3 flare that began 1991-07-31 00:46 UTC; No. 21 of 3,297 C-class-or-larger flares in 1991.