El Niño is poised to gather force fast between July and September, raising the risk of destructive weather around the world, the United Nations’ weather and climate agency has warned.
The World Meteorological Organization said the climate pattern is already under way and is expected to strengthen quickly, urging governments to prepare for its effects.
El Niño is a naturally occurring climate pattern that heats surface waters in the central and eastern equatorial Pacific Ocean, disrupting winds, air pressure and rainfall patterns across the globe.
It usually emerges every two to seven years and tends to persist for roughly nine to 12 months.
In its monthly Global Seasonal Climate Update, the WMO said current signals point to “a rapid development into a strong El Niño event during July-September”.
The UN body ranks El Niño episodes as weak, moderate, strong or very strong, placing the expected event at the third of four intensity levels.
“El Niño conditions have developed in the tropical Pacific and are forecast to strengthen rapidly over the coming months, increasing the likelihood of… extreme weather events in many parts of the world,” the WMO said.
Heatwave risks
The Geneva-based agency said forecasts from leading global climate centres, based on a range of models, show sustained and substantial warming in ocean temperatures across the central and eastern equatorial Pacific.
“Seasonal-average sea-surface temperature anomalies expected to exceed 2C in key monitoring regions,” it said.
The WMO added that the models were in “remarkable agreement”, giving forecasters strong confidence in the outlook.
“El Niño is expected to continue strengthening during the Northern Hemisphere autumn, with its influence extending across many regions of the globe.
“Meanwhile, the equatorial Atlantic basin is expected to remain generally warmer than average.”
The previous El Niño helped push 2023 to become the second-hottest year ever recorded and 2024 to the hottest on record, at about 1.55C above the 1850-1900 pre-industrial average.
Although El Niño commonly reaches its peak between November and February, the surge in global temperatures linked to it often arrives later.
“El Niño conditions are already under way and are forecast to strengthen rapidly into a strong event,” WMO chief Celeste Saulo said.
“This will intensify the chances of drought and heavy rainfall and the risk of heatwaves on land and marine heatwaves in many regions.”
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The WMO said it was expanding early warning support to help shape preparedness efforts, particularly in climate-sensitive areas such as agriculture and health.
“Advanced seasonal forecasts and early warnings are vital to save lives and cushion the impact on our economies and our communities,” she said.
Temperature impact
The update forecasts an overwhelming chance of above-average temperatures across most land areas between 60 degrees south and 60 degrees north, spanning nearly all populated parts of the world outside the polar regions.
It also said the rainfall outlook for July to September matches a strengthening El Niño pattern, with wetter-than-normal conditions expected in some places, including parts of the southwestern United States, and drier-than-normal weather forecast across the Indian subcontinent and much of Australia.
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The WMO said there is no evidence that climate change makes El Niño events more frequent or more intense.
But the agency believes global warming can magnify their consequences, because hotter oceans and a warmer atmosphere provide more energy and moisture for extreme weather, including heatwaves and torrential rain.
In the northern hemisphere summer, the unusually warm waters linked to El Niño can help power hurricanes in the central and eastern Pacific, while suppressing their development in the Atlantic Ocean.
