weather term
El Niño and La Niña
Opposite phases of a recurring Pacific Ocean pattern that shifts global weather by changing sea-surface temperatures near the equator.
El Niño is the warm phase, when surface water in the eastern tropical Pacific warms above average, while La Niña is the cooler opposite phase. Both shift the position of major atmospheric circulation patterns, which is why a strong El Niño or La Niña can influence rainfall and temperature patterns on the other side of the world, from droughts in one region to wetter-than-average winters in another, even though the ocean warming itself happens thousands of kilometres away.