Strongest El Niño in a century? What this rare phenomenon could bring

For example, the Western United States, parts of Africa, Europe and India could face a hotter-than-average summer, some tropical countries, such as those in the Caribbean and Indonesia, could face worse drought and extreme heat, while more tropical cyclones could develop in the Pacific, with fewer in the Atlantic.

This possible super El Niño could also push global temperatures to record levels, particularly in 2027, and have agricultural impacts as weather patterns change.

“Real potential for the strongest El Niño event in 140 years,” wrote Paul Roundy, a professor of atmospheric science at the State University of New York at Albany.

Global impacts from a super El Niño

This year’s potential super El Niño seems increasingly likely to have wide-reaching climate impacts that last into 2027. Illustration / Getty Images

This year’s potential super El Niño seems increasingly likely to have wide-reaching climate impacts that last into 2027.

It could break the record for El Niño intensity set in December 2015, when sea temperatures in the central equatorial Pacific reached 2.8C above average.

Still, even as some signs point to a potent event, including a rare triplet-cyclone pattern brewing in the Pacific, uncertainty remains as to how strong this year’s El Niño will become. Furthermore, no two El Niño events are alike – especially as the climate warms – but past experiences can be used to help plan and prepare.

Here are some of the weather impacts predicted to unfold through to at least October, according to the newest model outlook.

Reduced hurricane activity in the Atlantic Ocean and possible drought in the Caribbean islands. Increased hurricane and typhoon risk in the Pacific Ocean, including Hawaii, Guam and much of eastern Asia.Potential drought in central and northern India, suppressing rainfall from that region’s monsoon season, which could impact agricultural production.Above-average summer temperatures and humidity in the Western United States, possibly coming with unusual downpours, which may reach into the Plains and extend severe thunderstorm season.Developing droughts in portions of Central Africa, Australia, Indonesia, the Philippines, some South Pacific islands, Central America and northern Brazil, particularly later in the year. Flooding downpours in Peru and Ecuador, parts of northern and eastern Africa, the Middle East and near the equator in the Pacific.Higher frequency of heat waves across large parts of South America, the southern United States, Africa, Europe, parts of the Middle East, India and eventually Australia.New global temperature records – especially in 2027 – probably breaking records set in 2024.The remains of homes in Savusavu, on the south coast of Vanua Levu island, after Tropical Cyclone Yasa tore through Fiji in December 2020. Photo / Tinnah Tagiteci

The strongest El Niño events almost always cause a record-warm year. That’s because heat comes out of the ocean during El Niño, overspreads the tropics in the Pacific, then gets redistributed across the planet by changes in the jet streams.

This could contribute to milder winter temperatures in the United States – and big storms along the West Coast – as the impacts of El Niño reach a peak from the end of the year into early 2027.

As the planet warms, El Niño behaves differently

Strong El Niño periods often appear as an upward stairstep in long-term plots of global temperatures.

“Due to the increasing concentration of greenhouse gases, the climate system cannot effectively exhaust the heat released in a major El Niño event before the next El Niño comes along and pushes the baseline upward again,” US Defence Department meteorologist Eric Webb said.

Therefore, a super El Niño in 2026-27 would disperse more heat than other events in 1982-83, 1997-98 and 2015-16.

Not only would a super El Niño spread unusual heat and humidity far and wide, but it may also spark record atmospheric moisture flows, which drive downpours that raise the risk for floods. That’s because a warmer atmosphere has a higher moisture-carrying capacity.