What is El Niño?
El Niño is the warm phase of ENSO, a coupled ocean-atmosphere pattern in the tropical Pacific.
How it works and what the evidence shows
Core idea Warmer-than-usual surface waters in the central and eastern tropical Pacific occur with changes in trade winds and rainfall. Ocean and atmosphere influence each other; it is not a single hot day. Evidence and research Scientists monitor sea temperature, wind and pressure together. La Niña is the cool phase, and neutral conditions also occur. Events vary in strength and impact.
Uses and limitations
Why it matters ENSO helps assess seasonal climate probabilities and can alter regional rain or drought risks. It does not by itself explain an individual storm. Common misunderstandings El Niño is different from human-driven global warming. It can influence a particular year’s global average, while long-term climate trends require separate analysis.