Solar Flare WatchHome › Flare history › 1999
X1.8 solar flare on 1999-10-14
ClassX1.8NOAA report
Peak09:001999-10-14 UTC
Duration9 min
Peak flux1.8e-04W/m²
| Comparison | Value |
|---|---|
| Rank among X flares (1975 – Jun 2017) | 222 / 491 |
| Rank in year | 1 / 2025 |
| Other M/X flares that day | 0 |
| M/X flares that month | 9 |
| Solar cycle | Cycle 23 |
| Position on disk | N11E32 |
| Active region | AR 8731 (20 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
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.
← X1.1 1999-08-28M8.0 1999-11-14 →
About this page
A X1.8 flare that began 1999-10-14 08:54 UTC; No. 1 of 2,025 C-class-or-larger flares in 1999.