Record-Breaking El Niño Expected to Intensify Global Weather Impacts

The 2023-24 El Niño is projected to become the strongest event documented in the instrumental record, according to the U.S. National Oceanic and Atmospheric Administration. Models from Berkeley Earth indicate that average sea-surface temperatures in the Niño 3.4 region could rise 3.6 °C above normal, surpassing the previous peak set during the 2015-16 event.

El Niño is defined when sea-surface temperatures in the central-eastern equatorial Pacific exceed 0.5 °C above average for three consecutive overlapping three-month periods. The phenomenon weakens east-to-west trade winds, allowing warm water to accumulate near South America and altering global atmospheric circulation.

Historical strong events have been linked to varied regional effects: increased winter precipitation in the U.S. Southwest, reduced rainfall in the Pacific Northwest, milder Atlantic hurricane seasons, heightened drought risk in Indonesia, southern Africa and parts of Australia, and warmer winters in Japan and Brazil. The current event is expected to follow similar patterns, though exact outcomes will depend on interacting climate factors.

Scientists use the informal term “super El Niño” for events where temperatures rise at least 2 °C above average; the 2023-24 episode meets that criterion. Past strong episodes, such as those in 1982-83, 1997-98 and 2015-16, produced notable hydrological extremes, including record snowfall in the Colorado River basin and severe droughts in Indonesia and southern Africa.

“There is a greater than 90 percent probability that this El Niño will be very strong this fall and winter,” NOAA said.

The heightened oceanic heat is expected to contribute to a global temperature spike and could generate economic losses estimated in the trillions of dollars by the early 2030s, according to climate impact assessments.