NASA: Explore El Niño
NASA explains the global climate pattern El Niño, characterized by warmer-than-average sea surface temperatures in the central and eastern Pacific Ocean. The phenomenon influences weather worldwide, altering rainfall patterns, temperatures, and storm activity, and NASA monitors it using satellites to better predict its impacts.
Background
El Niño is a natural climate pattern in the tropical Pacific Ocean that occurs every 2–7 years, lasting 9–12 months. During an El Niño, trade winds weaken and warm water shifts eastward toward the west coast of the Americas, altering global weather: it typically brings wetter conditions to the southern U.S. and drier weather to Southeast Asia and Australia. The opposite phase, La Niña, brings cooler ocean temperatures and different weather effects. Together they form the El Niño-Southern Oscillation (ENSO), the planet's most influential year-to-year climate fluctuation. NASA monitors El Niño using satellites, buoys, and computer models to predict its impacts on rainfall, droughts, floods, hurricanes, and agriculture worldwide. Understanding El Niño matters because it affects food security, water resources, and disaster preparedness for billions of people.