ENSO Neutral Condition
Published on 15 Oct 2025
The recent La Niña event in the tropical Pacific has officially ended, according to the United States’ National Oceanic and Atmospheric Administration (NOAA).
However, Oceanic and atmospheric patterns now reflect ENSO-neutral conditions — a phase expected to persist through the Northern Hemisphere summer, with a greater than 50% likelihood lasting into the autumn.
ENSO, or El Niño Southern Oscillation, is a recurring climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean.
It affects not only sea-surface temperatures (SST) but also wind patterns, atmospheric pressure and rainfall across large parts of the globe.
La Niña and El Niño are the two opposing phases of ENSO.
ENSO-neutral, by contrast, describes a state where neither El Niño nor La Niña is dominant.
While neutral phases tend to make global seasonal forecasts more uncertain, they are often a transitional period between the two more extreme phases.
This quick shift to neutral conditions happened as warm water spread westward across the eastern Pacific and the pool of cooler water below the surface began to shrink.
Some signs of La Niña in the atmosphere (like strong trade winds) were still present, but without the cold surface water, the system no longer qualified as La Niña.
