The El Niño climate event is expected to intensify further ahead of its forecast peak in December, with sea-surface temperatures in the central and eastern tropical Pacific projected to reach record levels, according to the World Meteorological Organization (WMO).
The latest WMO Global Seasonal Climate Update warns that the strengthening El Niño will continue to influence weather patterns around the world, increasing the likelihood of above-average temperatures and shifting rainfall patterns that could raise the risk of drought and flooding in different regions.
WMO Secretary-General Celeste Saulo said the climate event was already firmly established and was strengthening rapidly.
“El Niño is firmly established and strengthening rapidly. WMO forecasts indicate a near-100 per cent likelihood that it will persist through February 2027, potentially being one of the strongest since at least 1950,” Saulo said.
The latest assessment is based on a consensus involving 13 national and international centres, drawing on real-time observations from ocean buoys, satellites and radiosondes coordinated through the WMO.
Sea-surface temperature anomalies in the central-eastern equatorial Pacific, measured using the Niño 3.4 index, have risen sharply. The anomaly increased from 1.6 degrees Celsius above normal in June to 2.5°C above normal in August.
For October to December, the seasonal average Niño 3.4 temperature anomaly is forecast to reach approximately 3.7°C, with the warming expected to peak around December. If confirmed, this would be the highest level since observations began and would exceed the previous record of 2.6°C recorded between November 2015 and January 2016.
Saulo said the unusually warm ocean is providing the energy behind the strengthening event.
“El Niño doesn’t add new heat to the planet. It releases heat the ocean has already been storing beneath the surface – which is why a strong event so often becomes one of the hottest years measured (as with 2024),” she said at the Global Heat Forum in Bangkok.
“The ocean it’s drawing from is the warmest we’ve ever measured it. There is simply more heat available to release,” she added.
The strengthening El Niño is expected to have significant consequences for agriculture, water resources, ecosystems and communities as rainfall and temperature patterns change.
The WMO forecast points to wetter-than-normal conditions across the Greater Horn of Africa, as well as parts of Central Asia, coastal East Asia, northern areas of the Arabian Peninsula, parts of North America and southeastern South America.
In contrast, drier-than-normal conditions are forecast across the Indian subcontinent, southern Central America and parts of the Caribbean and northwestern South America.
The Indian Ocean is also expected to influence the seasonal outlook. A positive Indian Ocean Dipole is forecast to peak in October before declining, with its October-December seasonal anomaly projected at about +0.5°C. Meanwhile, sea-surface temperatures in the equatorial Atlantic are expected to remain above normal.
The WMO stressed that seasonal forecasts indicate broad probabilities rather than specific day-to-day weather conditions. Nevertheless, the strengthening El Niño signal is prompting continued preparedness efforts by meteorological agencies and humanitarian organisations.
The agency said its members are working with decision-makers and regional climate outlook forums to provide updated information to support preparedness and risk management.
With the event expected to intensify until December and persist into early 2027, governments and climate-sensitive sectors are being urged to use available climate information to prepare for potential impacts ranging from extreme heat and flooding to drought and disruptions to agriculture and water resources.
