The United Nations has warned the world to brace for potentially record high temperatures this summer amid the rising likelihood of an El Niño event during the summer months.

The World Meteorological Organization (WMO) has issued a new  El Niño/La Niña Update indicating an 80% likelihood of an El Niño event during June–August 2026. Probabilities for this to continue until at least November are near or above 90%. Although some uncertainty remains about El Niño peak strength and timing, most forecast models suggest it will be at least moderate – and possibly strong.

The result is concerns that this may well deliver record breaking temperatures across the planet.

“The science is clear: El Niño is arriving on our doorstep in the coming months with 90% certainty. The world must treat it as the urgent climate warning it is. El Niño conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even farther, and cross borders with devastating speed. The only effective response is climate action equal to the crisis – ending the addiction to fossil fuels, accelerating the shift to renewables, protecting the most vulnerable, and delivering early warning systems for all.” said UN secretary-general António Guterres.

The WMO explained in late April to mid-May, the sea-surface temperature in the central-eastern Equatorial Pacific – the area used as a monitoring reference – was approaching El Niño thresholds, according to observations from different platforms used by the organisation.

These increasing surface anomalies are being fed by unusually warm subsurface conditions across the tropical Pacific, with temperatures exceeding 6 °C above average and providing a substantial reservoir of heat that is contributing to the observed surface warming.

Meanwhile, the Southern Oscillation Index – which is the atmospheric component of El Niño – is also consistent with developing El Niño conditions.

“We need to prepare for a potentially strong El Niño event – which will exacerbate drought and heavy rainfall and increase the risk of heatwaves both on land and in the ocean. The most recent El Niño, in 2023-24, was one of the five strongest on record and it played a role in the record global temperatures we saw in 2024,” said WMO secretary-general Celeste Saulo. “The WMO community will be carefully monitoring conditions in the coming months to inform decision-making by governments, humanitarian agencies, and climate-sensitive sectors. Advance seasonal forecasts and early warnings are vital to save lives and cushion the impact on our economies and our communities.”

WMO has issued a complementary Global Seasonal Climate Update – which takes into account other climate drivers, enabling more refined regional forecasts.

Each El Niño event is unique in terms of its evolution, spatial pattern, and impacts.

However, it is typically associated with increased rainfall in parts of southern South America, the southern United States, parts of the Horn of Africa and central Asia, and drier conditions over Central America, northern South America, the Caribbean, Australia, Indonesia, and parts of southern Asia.

The WMO also issued a complementary Global Seasonal Climate Update which takes into account ENSO and other key climate drivers, such as the North Atlantic Oscillation, the Southern Annular Mode and the Indian Ocean Dipole – which correlates closely with El Niño in the Pacific and which may develop into a positive phase, peaking concurrently with the intensifying El Niño.

“For the June-July-August season, forecasts project a nearly universal dominance of above-normal temperatures in nearly all parts of the globe,” it added. “These increase risks of heat stress and compounding hazards in some regions and accelerate the development of drought conditions where rainfall is reduced.

“Rainfall probabilities are typical of El Niño patterns and this is likely to contribute to a greater probability of extremes including. increased rainfall and flooding, as well as drier conditions and droughts.”