Are we heading for ‘super El Niño’ – and what could we expect?

There is a high likelihood that the phenomenon known as “El Niño” will emerge this summer – and it could be exceptionally strong. A so-called “super El Niño” could supercharge extreme weather events and push global temperatures to record heights next year if it develops, according to experts.

Meteorologists are keeping a close eye on the climate patterns developing in the Pacific Ocean that will enable stronger predictions about what’s to come in the year ahead.

A strong El Niño would put 2027 in the running to break global heat records, and could produce a series of devastating effects, ranging from supercharged rainstorms to drought depending on the region of the world.

While it’s not “a slam dunk”, climate scientist and media director for Climate Central Tom Di Liberto said during a briefing held on Thursday that the ingredients for El Niño are there. Forecasts inspring can’t account for unexpected changes that can happen over the summer, he added, but “the risk is high enough to be worried”.

Here’s what you need to know:

What is El Niño?

The ocean and the atmosphere are inextricably linked. That’s why forecasters look closely at ocean temperatures and conditions to help predict future weather patterns around the world.

El Niño is characterized by warming of the ocean surface in the central and eastern tropical Pacific Ocean. It’s one of three states scientists observe: La Niña, conversely, happens when sea surface temperatures are below average, and neutral conditions are defined when neither El Niño or La Niña are present and surface temperatures are about average.

These three states together form the “El Niño-southern oscillation” (Enso), which tends to develop during spring in the northern hemisphere and shifts every three to seven years, according to the US National Weather Service. Warming and cooling at sea surface during El Niño and La Niña can range from 1C to 3C, and have enormous effects on precipitation, drought, heat and climate disasters in different regions, depending on which direction they go.

During Niño years, the winds that would push warm waters to the west soften or shift direction, enabling the surface waters in that part of the Pacific to warm. Characterized by temperatures at least 0.5C above the norm, these conditions massively impact the weather and often push global temperatures to new heights.

Climate scientists are quick to point out that each event is unique and there’s considerable variability between them, in intensity and outcomes. But Enso predictions can help people around the world prepare for coming shifts in extreme weather – an essential tool in a warming world.

Conditions are currently shifting from La Niña to a neutral pattern, according to the latest outlook from the US Climate Prediction Center released on 6 April, but models are showing a 62% chance El Niño will emerge this summer and linger until at least the end of the year.

How will El Niño affect weather events?

While there are many factors that create weather, El Niño can create a massive atmospheric upset. It alters jet streams and flips precipitation patterns, fueling more severe storms in some parts of the world, while desiccating others. It also has the power to spike rising temperatures even higher, at least briefly.

A super El Niño that occurred in 2015 brought severe drought in Ethiopia, water supply shortages in Puerto Rico, and smashed records after unleashing a vicious hurricane season in the central North Pacific, according to an analysis by US federal scientists.

The cycle tends to create drought and heat across Australia, around southern and central Africa, in India and in parts of South America, including in the Amazon rainforest. Heavy precipitation, meanwhile, could hit the southern tier of the US, parts of the Middle East, and south-central Asia.

Deluges could come as a welcome relief for thirsty states in the US hoping water supply shortages caused by this year’s dire snowpack might be bailed out by a strong summer monsoon and wetter winter next year. But as Di Liberto pointed out, these dry conditions have largely been fueled by heat, and it’s less likely that these regions will get a reprieve from rising temperatures.

“It’s important to note when we are talking about the drought, a lot of it has been temperature-driven and not precipitation-driven,” he said.

Experts have also said most devastatingly dry basins won’t be able to rebound after one wet season. That’s particularly true in the US south-west where some reservoirs are at an all-time low.

“Just because we’re expecting a large-scale change in the climate pattern doesn’t necessarily mean that we’re going to see drought completely erased,” Dr Joel Lisonbee, senior associate scientist at the Cooperative Institute for Research at the University of Colorado Boulder said. “It would have to be exceptionally wet,” he added. “That would also mean flooding, and the destruction and potential loss of life that comes along with that.”

Why are scientists talking about a ‘super El Niño’?

A “super” El Niño just means one that is stronger. These are rare events typically defined by sea surface temperatures spiking up by at least 2C. This has only occurred a few times since 1950 and only once have temperatures surged past 2.5C.

The higher they go, the higher the likelihood that impacts from El Niño would be supercharged. Noaa scientists have given a 1 in 4 chance that this could happen by fall or winter, with the caveat that spring forecasts are sometimes muddled. Transitions in conditions that happen in the spring can make outcomes a bit harder to predict. But there are already key indicators that a strong or super El Niño could be forming.

Dr Paul Roundy, a professor of Atmospheric and Environmental Sciences at the State University of New York at Albany, wrote this week that there was “real potential for the strongest El Niño event in 140 years”. Dr Andy Hazelton, associate scientist at the University of Miami wrote: “All models and observations are pointing in the same direction: a very strong El Niño with significant impacts on global climate this year.”

How likely is this to happen?

While the models show a good chance that something big could develop, experts have also pointed out these readings tend to skew higher because of overall warming trends that affect baselines.

“We have this underlying warming trend that makes our El Niños look bigger than they really are and makes our La Niñas look smaller than they really are because everything’s just getting warmer,” said Lisonbee. This year, Noaa began using a new model to better identify what might be an anomaly and what’s tied to overall warming, but other tools still rely on historical data.

Spring also tends to not provide the clearest picture, due to natural transitions that happen during this time of year. “Even though our models are predicting El Niño right now and some models are predicting a very strong one, I would not be surprised to see the forecast change over the next few months,” Lisonbee said. “We call it the spring predictability barrier, and the models tend to change quite a bit from one model run to the next.”

Even so, the probability is still high that El Niño will develop later this year. How strong it will be remains to be seen. But with conditions beginning to coalesce around the possibility for a severe shift, officials around the world are pushing for preparation.

“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 the World Meteorological Organization secretary general, Celeste Saulo, in a written statement, adding that officials are carefully monitoring conditions to inform key decisions.

“Seasonal forecasts for El Niño and La Niña help us avert millions of dollars in economic losses and are essential planning tools for climate-sensitive sectors like agriculture, health, energy and water management. They are also a key part of the climate intelligence provided by WMO to support humanitarian operations and disaster risk management, and thus save lives,” she said.