La Niña (, ) is a coupled ocean-atmosphere phenomenon that is the counterpart of
El Niño as part of the broader
El Niño–Southern Oscillation climate pattern. The name La Niña originates from
Spanish, meaning "the girl", analogous to El Niño meaning "the boy". It has also in the past been called
anti-El Niño, and El Viejo (meaning "the old man"). During a period of La Niña, the
sea surface temperature across the equatorial Eastern Central
Pacific Ocean will be lower than normal by 3–5 °C. In the United States, an
appearance of La Niña happens for at least five months of La Niña conditions. It has extensive effects on the weather in
North America, even affecting the
Atlantic Hurricane Season. A La Niña often, though not always, follows an El Niño.