Critical parts of the central and eastern Pacific Ocean remain in a holding pattern, with neither La Niña nor El Niño in control as the fall approaches.
NOAA forecasters said a transition from ENSO-neutral to La Niña could still happen during the remaining months of 2025, but probabilities will begin decreasing significantly by the start of the new year.
The El Niño–Southern Oscillation, commonly referred to as ENSO, is made up of three phases – El Niño, La Niña and neutral – which can impact climate patterns worldwide.
ENSO is considered to be in a neutral state when regions of the central and eastern Pacific have anomalies between 0.5 and -0.5 degrees Celsius.
The world has been in a neutral state since mid-2025, when water temperature anomalies rose out of La Niña status.
IS THERE A WEATHER PHENOMENON KNOWN AS THE ATLANTIC NINA?
According to NOAA, August’s values ranged between -0.2 and -0.4 C, which is outside the threshold for declaring La Niña underway but close enough to continue what is known as a “La Niña Watch.”
There appears to be a fork in the road, with one group of significant models suggesting the world will not reach La Niña status during this cycle, while others point to a brief period of La Niña conditions.
Based on guidance and cooling trends in the Pacific, NOAA forecasters said they are leaning toward a weak La Niña developing in the coming months. However, even if the world does reach that status, there likely will not be significant changes in weather patterns.
Forecast model predictions of ENSO status
(FOX Weather)
During neutral ENSO cycles, the jet stream tends to have fewer kinks, and more regional patterns control local weather.
This usually means winters in the southern U.S. stay warmer than average, while the northern U.S. is cooler. The transition zone is often situated over the Ohio Valley.
During La Niña events, precipitation chances often increase across parts of the U.S., while drier weather impacts the southern tier of the country. The nation as a whole typically experiences cooler-than-average conditions.
LITTLE-KNOWN WEATHER PATTERN WHEN EL NINO AND LA NINA ARE NO LONGER IN CONTROL
Last winter officially qualified as a La Niña event, although the signal was weak.
Despite the typical cool signal, the season ended as the third-warmest winter on record, with NOAA reporting an average temperature of 1.9 degrees Fahrenheit above the long-term average.
There are only two more scheduled ENSO updates before the start of meteorological winter, which begins Dec. 1 and runs through the end of February.
Typical La Nina Pattern
(NOAA’s Climate.gov)
