El Niño has begun, and extreme weather looms

El Niño has officially started after ocean temperatures rose more than 0.5°C above normal in the central-eastern Pacific. NOAA says there’s a 63% chance it will become a very strong “super” El Niño, amplifying heat and shifting rainfall patterns—raising risks

By the time people noticed the shift, the ocean had already started doing what it does in El Niño: letting warm water travel east.

NOAA has now declared the onset of El Niño because sea surface temperatures in the central-eastern Pacific have been more than 0.5°C above normal for the past month. and climate models project they will remain there for at least the next six months. The Japan Meteorological Agency has also declared that El Niño has begun.

El Niño is a natural climate phase that occurs when east-to-west winds weaken in the tropical Pacific. allowing water concentrated in the “warm pool” on the western side of the Pacific to wash back towards the eastern side. That broad smear of warm water heats the atmosphere, raising the global temperature.

At NOAA’s National Weather Service, Matthew Rosencrans described what the wind changes look like across the ocean. “We are seeing westerly wind anomalies from the dateline almost all the way to about 130° west. so basically the entire area south of Hawaii. ” he said. “What that means is significantly reduced trade winds there. so it’s allowing the atmosphere and the ocean to slosh to the east and bring that warm water with it.”.

The warning now is not just about a phase of the climate, but about how intense it could become. NOAA said there is a 63 per cent chance this El Niño will develop into a very strong or “super” El Niño. when sea surface temperatures in the equatorial Pacific breach 2°C above average. It could be the hottest El Niño ever seen.

Adam Scaife at the Met Office, the UK’s weather service, put it bluntly in a statement: “This latest El Niño is likely to be a significant event, perhaps one of the most intense on record.”

In the models, the atmosphere does not seem ready to let up. Out of 200 model simulations. none show sea surface temperatures in the central-eastern Pacific going back below 1°C this year once El Niño gets going. Rosencrans said. Several models project sea surface temperatures could reach 2.6°C, and one Canadian model says they could even hit 3°C. That would smash the 2.5°C record set during the super El Niño of 1982-83.

Back then, the consequences were deadly. During the 1982-83 event, flooding killed an estimated 1300 to 2000 people in Peru.

This time, temperatures are expected to peak this winter and simmer well into 2027. The heat is arriving on top of global warming of 1.36°C, pushing scientists to predict that next year will be the hottest ever observed.

A warmer atmosphere can hold more energy and moisture, and that changes the odds of extreme weather. El Niño tends to bring abnormally wet or dry conditions to different regions.

“What it does is change the odds of those rainfalls or heatwaves or cold snaps happening in certain places. ” Rosencrans said. “The atmosphere [is] throwing loaded dice in a way. so you’re more likely to get rainfall in southern California. you’re more likely to get drying in the maritime continent. and potentially even into India [and] the northern parts of Australia.”.

For the southern United States. that means reduced rainfall this summer. followed by cool. wet. stormy weather this winter. with cold snaps possible as far south as Mexico. For South-East Asia and south-east Africa. the pattern could lean toward heat and drought this summer and winter—raising the risk of wildfires.

In Europe, the picture is less straightforward. El Niño can tend to bring colder winters to the UK. but it can also bring warmer. wetter conditions. Ella Gilbert—an independent climate scientist—said during a briefing. “Many other climate factors affect Europe, meaning El Niño impacts are less certain,” she said. “It tends to change the storm tracks, and you often get these warmer, wetter conditions.”.

Gilbert added that, in the past for the UK, there have been more storm incidents than otherwise, though “the direct connection in the UK is less obvious than in the US or Australia.”

The knock-on effects do not stop at weather maps. Heat or drought can hit commodities such as rice, coffee and chocolate, disrupting food supplies around the world.

Weston Anderson at the University of Maryland warned that if rice yields decline. India—a major producer—could limit exports. making rice scarcer and more expensive elsewhere. “The impacts… ripple through the food system,” he said. “We think about a commodity like rice. which is important for food security for many people. and we do have concerns about potential monsoon deficits leading to lower rice production.”.

And for governments and communities, the timing matters as much as the science. Chloe Brimicombe at the University of Oxford said El Niño may be getting more frequent. and global warming will “regardless exacerbate its consequences. ” potentially compounding problems such as migration. “We need long-term preparedness and planning as we continue with climate change and we also continue with El Niño amplifying that.”.

For now, the start is official and the direction is clear: a natural shift has begun, but the warming world it arrives in could make the impacts harder to live with.

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