Solar Flare WatchHome › Flare history › 1991
X1.0 solar flare on 1991-04-20
ClassX1.0NOAA report
Peak08:521991-04-20 UTC
Duration177 min
Peak flux1.0e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 414 / 491 |
| Rank in year | 49 / 3297 |
| Other M/X flares that day | 2 |
| M/X flares that month | 42 |
| Solar cycle | Cycle 22 |
| Position on disk | N08W50 |
| Active region | AR 6583 (24 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 |
|---|---|---|---|---|---|---|
| 06:19 | 06:29 | 25 | M1.5 | – | – | |
| 08:42 | 09:01 | 52 | M3.5 | – | – |
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.
← M9.8 1991-04-15M8.2 1991-05-13 →
About this page
A X1.0 flare that began 1991-04-20 08:27 UTC; No. 49 of 3,297 C-class-or-larger flares in 1991.