2017-18 El Niño Event
Strength Weak
ENSO Temp. Change +0.6C
Started September/October/November 2017
Ended March/April/May 2018
The 2017-18 El Niño event was a warming of the equatorial Pacific Ocean. This El Niño was somewhat weaker than the very strong El Niño two years ago but still produced adverse effects. This El Niño also had one of the shortest durations and intensities among recent El Niño events.

The warmest anomalies were mainly concentrated in the central Pacific Ocean. As a result this El Niño was more of a "Modoki" type El Niño, with near neutral ENSO conditions in the Niño 1.2 region. As a result of the event 2017 was the second-warmest year on record on Earth globally behind only 2016.


By early 2017 meteorologists began to note the possibility of the return of El Niño in summer or autumn 2017. El Niño struggled to develop as quickly as models originally predicted, with ENSO conditions remaining neutral well into late summer. In May 2017 the Climate Prediction Center (CPC) issued an El Niño Watch, which was later canceled in August after the warm anomalies failed to appear as soon as forecast. However in October 2017 the watch was re-instated with El Niño being officially declared one month later. The Oceanic Niño Index (ONI) barely managed to cross the El Niño threshold for five consecutive months, enough to classify 2017-18 as an El Niño year according to NOAA. However, the Australian Bureau of Meteorology never even said 2017-18 ever reached true El Niño conditions.

Since the El Niño event was somewhat weak, it did not have as strong of an effect on hurricane season as most El Niño events do; the 2017 Atlantic hurricane season was near average overall with a total of 13 named storms 5 hurricanes and 2 major hurricanes.