Solar Flare WatchHome › Flare history › 1999
X1.1 solar flare on 1999-08-28
ClassX1.1NOAA report
Peak18:051999-08-28 UTC
Duration26 min
Peak flux1.1e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 374 / 491 |
| Rank in year | 4 / 2025 |
| Other M/X flares that day | 1 |
| M/X flares that month | 25 |
| Solar cycle | Cycle 23 |
| Position on disk | S26W14 |
| Active region | AR 8674 (29 flares) |
Compared with the strongest flares of 1999
X1.8
X1.4
X1.4
X1.1
M9.8
M8.0
M7.6
M7.4
M6.6
M6.2
M6.0
M6.0
Other M/X flares that day
| Date | Begin | Peak | Min | Class | Location | Region |
|---|---|---|---|---|---|---|
| 00:50 | 01:02 | 26 | M2.8 | S26W16 | 8674 |
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.
← M5.5 1999-08-27X1.8 1999-10-14 →
About this page
A X1.1 flare that began 1999-08-28 17:52 UTC; No. 4 of 2,025 C-class-or-larger flares in 1999.