UN warns of ‘supersized’ El Niño as extreme weather risks rise

The world has entered a “danger zone of extreme weather” as a potentially unprecedented El Niño begins to intensify, UN Secretary-General António Guterres has warned.

The World Meteorological Organization (WMO) said the natural climate phenomenon could become the strongest El Niño since at least 1950, with impacts expected to be felt across the world into 2027.

“El Niño is being supersized before our eyes. The science leaves no room for doubt: the planet is in uncharted waters, and those waters are heating up,” Guterres said.

El Niño develops when ocean temperatures in the central and eastern tropical Pacific rise significantly above normal. The resulting changes in atmospheric circulation and winds can disrupt weather patterns far beyond the Pacific, bringing drought to some regions while increasing the risk of floods, storms and typhoons elsewhere.

Sea surface temperatures in the key monitoring region have already risen to more than 2°C above average in recent weeks. Forecasts suggest monthly temperatures could approach 4°C above average, potentially pushing the event into an exceptionally strong category. Temperatures below the ocean surface are even more unusual, exceeding average levels by more than 8°C in some areas.

Drought and wildfire risks

The WMO expects major shifts in rainfall over the coming months.

Drier-than-usual conditions are forecast across large parts of Southeast Asia, Central America and northern South America, increasing the risk of drought and wildfires.

Indonesia is already battling fires that have burned more than 107,000 hectares during the current dry season. Authorities have deployed cloud-seeding aircraft in an attempt to generate rain and suppress the fires.

In Panama, rainfall concerns are already affecting trade. The authorities plan to reduce the number of vessels passing through the Panama Canal by more than 10% as lower rainfall threatens water availability for the crucial shipping route. About 14,000 ships use the canal each year.

Southern Africa could also face renewed drought risks. Countries such as Botswana experienced severe drought during the previous El Niño event.

Floods, typhoons and landslides

El Niño can have the opposite effect in other parts of the world.

China is expecting an unusually active typhoon season, with experts predicting seven typhoons could make landfall this year. Three typhoons — Bavi, Noul and Maysak — hit China in July, while Typhoon Dolphin forced more than one million people to evacuate in August.

Wetter-than-normal conditions are also forecast in parts of eastern Africa, southern Brazil and the southern United States, increasing the risk of flooding.

Peru, Ecuador and parts of Brazil are particularly vulnerable to heavy rainfall, flash floods and landslides during El Niño events, especially in urban areas where poor drainage can exacerbate flooding.

“We are already seeing disruption and devastation from droughts and floods and we expect these impacts to increase as El Niño intensifies,” said WMO Secretary-General Celeste Saulo.

Climate change adds to the threat

While El Niño is a natural phenomenon, its impacts are now unfolding against a backdrop of long-term human-caused global warming.

Scientists say rising global temperatures can make extreme heat more dangerous and intensify the consequences of droughts, floods and marine heatwaves. There is also research into whether climate change could make El Niño events stronger, although this remains uncertain.

Australia is already dealing with marine heatwaves linked to climate change, which have contributed to coral bleaching and algal blooms. Forecasts suggest southern Australia could experience stronger marine heatwaves this summer.

The Great Barrier Reef, however, may escape the worst of the conditions, giving its coral ecosystems more time to recover.

The WMO has launched what it described as a “major mobilisation” to ensure forecasts of El Niño-linked extreme weather reach vulnerable communities.

Countries are also strengthening early warning systems and preparing medical and emergency assistance in advance.

But experts warn that preparedness alone cannot eliminate the risks. Miguel Aréstegui of Practical Action said El Niño “does not arrive in a vacuum”, pointing to structural vulnerabilities such as housing in exposed areas, fragile water and sanitation systems and weak healthcare infrastructure.

The immediate challenge, therefore, is not simply the strength of El Niño itself but how effectively governments can prepare communities for the very different — and potentially extreme — weather conditions it could bring.