What is El Niño and how could it affect weather this year?

By — Maria Ramirez Uribe Maria Ramirez Uribe Leave your feedback Share Copy URL https://www.pbs.org/newshour/science/what-is-el-nino-and-how-could-it-affect-weather-this-year Email Facebook Twitter LinkedIn Pinterest Tumblr Share on Facebook Share on Twitter What is El Niño and how could it affect weather this year? Science Jun 4, 2026 6:28 PM EDT Scientists around the world are warning a strong El Niño this year, colloquially dubbed a super El Niño, could lead to extreme weather events — from heavy rainfall to exacerbated droughts. READ MORE: The U.S. smashed heat records in March. Just wait for El Niño this summer The National Oceanic and Atmospheric Administration predicted last month there's an 82% chance of El Niño emerging between May and July. The United Nation's World Meteorological Organization agrees, saying there's a 90% chance El Niño will continue until at least November. Grow your mind Subscribe to our Science Newsletter to explore the wide worlds of science, health and technology. "The world must treat it as the urgent climate warning it is," said U.N. Secretary-General António Guterres in a video statement . "El Niño conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even further and cross borders with devastating speed." The last El Niño event happened in 2023 and 2024 and "was one of the five strongest on record," according to World Meteorological Organization Secretary-General Celeste Saulo. Those years were marked by record high global temperatures, severe droughts and intense cyclones. Here's what to know about the weather phenomenon. What is El Niño? Trade winds usually push warm water in the Pacific Ocean from South America to Asia. During El Niño, the trade winds are weaker and the Pacific's warm water moves toward the Americas instead. El Niño is "the warm phase of a natural seesaw in the equatorial Pacific sea surface temperatures," said Robert Burgman, an atmospheric science professor at Florida International University. South American fishermen in the 1600s gave the weather pattern its name: El Niño, "the little boy" in Spanish, was a reference to baby Jesus. Every few years, the fishermen noticed warm waters around Christmas time. There's also an opposing weather pattern known as La Niña. Strong trade winds push more warm water to Asia while pushing even colder water to the Pacific coast of the Americas. What happens during El Niño? El Niño events tend to last for several months. They make "normally dry places wet and normally wet places dry," said Paul Roundy, professor of atmospheric and environmental sciences at the State University of New York at Albany. The weather pattern usually takes place every few years and tends to intensify in the fall, peaking in the winter, said Bob Henson, a meteorologist and journalist with Yale Climate Connections. In the U.S., El Niño's effects are often divided between the North and South. From fall to spring, the southern U.S. can see inc