This Year's El Niño Could Become the Strongest on Record
El Niño is intensifying in the Pacific Ocean at an unusually fast pace this year and could reach unprecedented strength. The event is expected to shift rainfall and temperature patterns worldwide and carries significant economic risks.
Weather agencies around the globe are closely tracking an unusually rapid buildup of El Niño in the Pacific, a phenomenon driven by warmer-than-normal sea surface temperatures near the equator. As heat stored in the ocean is released into the atmosphere, it sets off a chain of effects on rainfall patterns, air temperatures and even hurricane activity across the planet.
The US National Oceanic and Atmospheric Administration (NOAA) declares an official El Niño when sea temperatures in a defined central Pacific zone stay at least 0.5 degrees Celsius above average across three overlapping three-month periods. The event also weakens the trade winds, letting warm water pool on the ocean's eastern side — during the strongest past episodes, sea levels there rose more than 18 centimeters above normal.
El Niño shifts the odds of weather worldwide: wetter conditions are likelier in the US Southwest while the Pacific Northwest tends to see less rain, and Atlantic hurricane seasons often turn milder. At the same time, the odds of drought increase in Indonesia and southern Africa, while parts of Japan, Australia and Brazil tend to see warmer winters.
When El Niño turns 'super'
Scientists informally label an event a "super El Niño" once temperatures climb more than 2 degrees Celsius above normal — a threshold reached in 1982–83, 1997–98, 2015–16 and 2023–24. The 1982–83 episode brought record flooding to the Colorado River basin in the US, while 1997–98 triggered Indonesia's worst drought in roughly 50 years. The 2023–24 event contributed to southern Africa's worst drought in over a century, leaving about 61 million people in need of humanitarian aid.
NOAA now puts the probability at over 90 percent that this year's El Niño will become "very strong" by fall and winter. Modeling from Berkeley Earth suggests temperatures in the key Pacific region could rise 3.6 degrees Celsius above normal — surpassing the previous record set during the 2015–16 event by roughly 0.8 degrees, and developing even faster than the 1997–98 super El Niño.
The economic toll can be steep as well: one analysis estimated the 1997–98 El Niño caused roughly $5.7 trillion in cumulative losses over the following five years. Its cooler-ocean counterpart, La Niña, tends to produce the opposite effects, but forecasters expect El Niño to remain dominant at least through spring.
