Ocean temperatures are rising rapidly in the equatorial Pacific and drought and heat waves are expected in summer.
A “strong” El Niño (Little Boy) is on the way, the World Meteorological Organisation (WMO) recently announced.
“An El Niño event is expected to develop from mid-2026, impacting global temperature and rainfall patterns,” the WMO said.
SA Weather Service scientist Cobus Olivier said the predicted El Niño was only expected to impact the summer rainfall season starting around October to November.
He said El Niño typically brought drier and warmer summers but this depended on their strength.
There had only been a few “super El Niño” seasons — the 1982-83 El Niño had “one of the worst impacts on crops”, while the 1997/98 El Niño failed to produce a typical drier and warmer summer season.
“It’s still early to highlight any predictions for SA directly.
“There is a clear reduction in skill for predicting Enso [El Niño–Southern Oscillation] during winter.
“It is prudent to wait till around August or September before making any statements regarding the direct effect of the predicted El Niño and the impact on South Africa.
“In general, when one only looks at El Niño , ignoring their strength, they have the typical effect for drier and warmer seasons during summer.
“We need to stress that only the summer rainfall areas have been shown to be affected by Enso and we do not expect any significant impact during winter.”
The WMO said: “The latest monthly global seasonal climate update signals a clear shift in the equatorial Pacific: sea-surface temperatures are rising rapidly, pointing to a likely return of El Niño conditions as early as May–July 2026.”
It said its forecast was “supported by the accumulation of warmer than average subsurface waters in the equatorial Pacific, a key precursor for El Niño development”.
It said forecasts indicated a “nearly global dominance of above-normal land surface temperatures” in the upcoming three-month period, and regional variations in rainfall patterns.
“After a period of neutral conditions at the start of the year, climate models are now strongly aligned, and there is high confidence in the onset of El Niño, followed by further intensification in the months that follow,” said Wilfran Moufouma Okia, chief of climate prediction at the WMO.
“Models indicate this may be a strong event, but the so-called spring predictability barrier is a challenge for the certainty of forecasts at this time of year.
“Forecast confidence generally improves after April,” he said.
The WMO explained: “El Niño and La Niña are opposite phases of the El Niño–Southern Oscillation; one of the most powerful climate patterns on Earth.
“These events reshape global weather, influencing rainfall, drought, and extreme events across regions.
“Governments, humanitarian organisations, water managers, and farmers depend on accurate and timely Enso forecasts to anticipate and respond to risks.
“El Niño is characterised by a warming of ocean surface temperatures in the central and eastern Equatorial Pacific.
“It typically occurs every two to seven years and lasts around nine to 12 months.”
There is no evidence that climate change increases the frequency or intensity of El Niño events
The WMO said 2024 was the hottest year on record because of the combination of the powerful 2023-2024 El Niño and human-induced climate change from greenhouse gases.
It stated: “There is no evidence that climate change increases the frequency or intensity of El Niño events.
“But it can amplify associated impacts because a warmer ocean and atmosphere increases the availability of energy and moisture for extreme weather events such as heatwaves and heavy rainfall.
“Each El Niño event is unique in terms of its evolution, spatial pattern and impacts.”
It was typically associated with increased rainfall in parts of southern South America, the southern US, the Horn of Africa and central Asia, and drought over Australia, Indonesia, and parts of southern Asia.
“During the Boreal summer [northern summer], El Niño’s warm water can fuel hurricanes in the central/eastern Pacific Ocean, while it hinders hurricane formation in the Atlantic Basin.”
The WMO’s global seasonal climate update had taken into account other key climate drivers, such as the North Atlantic Oscillation, and the Southern Annular Mode or the Indian Ocean Dipole.
“For the May-June-July season, land surface temperatures are expected to be above-normal nearly everywhere.
“The signal is especially strong over southern North America, Central America, and the Caribbean, as well as Europe and Northern Africa.
“Rainfall predictions show strong regional variations.”
The WMO urged humanity to use its forecast to “guide preparedness actions, especially in climate-sensitive sectors like agriculture, water resource management, energy and health”.
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