Dennis Mersereau | @wxdam
Stick to the weather.
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El Niño and La Niña

A map showing the Niño 3.4 region in the eastern Pacific Ocean
The Niño 3.4 region covers an area between 170°W, 120°W, 5°N, and 5°S.

ENSO, short for the El Niño-Southern Oscillation, is a pattern of warmer- and cooler-than-normal waters in the eastern Pacific Ocean off the west coast of South America.

Fishermen back in the 1800s first noticed the warmer-than-normal waters around Christmastime, dubbing the phenomenon El Niño ('the little boy' in Spanish) in honor of the season.

An El Niño occurs when waters in the eastern Pacific around the equator are at least 0.5°C warmer than normal for seven consecutive months. La Niña occurs when waters in the same region are 0.5°C cooler than normal for the same period of time.

Forecasters focus on sea surface temperatures in a region called Niño 3.4, which offers the best sample of anomalies that can contribute to these patterns.

The two patterns have major effects on global weather patterns. El Niño often brings wet winters to the U.S. West Coast and dry heat to Australia and Oceania. La Niña tends to reduce wind shear blowing over the Atlantic Ocean, which can lead to an above-average Atlantic hurricane season.




ENSO Temperature Anomalies (°C) Since 1950

The list below shows three-month average sea surface temperature anomalies since 1950. Periods with an official El Niño are shaded in red, while stretches featuring La Niña conditions appear in blue.


Year DJF JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ Year DJF JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ
1950 -1.5 -1.3 -1.2 -1.2 -1.1 -0.9 -0.5 -0.4 -0.4 -0.4 -0.6 -0.8 1988 0.8 0.5 0.1 -0.3 -0.9 -1.3 -1.3 -1.1 -1.2 -1.5 -1.8 -1.8
1951 -0.8 -0.5 -0.2 0.2 0.4 0.6 0.7 0.9 1.0 1.2 1.0 0.8 1989 -1.7 -1.4 -1.1 -0.8 -0.6 -0.4 -0.3 -0.3 -0.2 -0.2 -0.2 -0.1
1952 0.5 0.4 0.3 0.3 0.2 0.0 -0.1 0.0 0.2 0.1 0.0 0.1 1990 0.1 0.2 0.3 0.3 0.3 0.3 0.3 0.4 0.4 0.3 0.4 0.4
1953 0.4 0.6 0.6 0.7 0.8 0.8 0.7 0.7 0.8 0.8 0.8 0.8 1991 0.4 0.3 0.2 0.3 0.5 0.6 0.7 0.6 0.6 0.8 1.2 1.5
1954 0.8 0.5 0.0 -0.4 -0.5 -0.5 -0.6 -0.8 -0.9 -0.8 -0.7 -0.7 1992 1.7 1.6 1.5 1.3 1.1 0.7 0.4 0.1 -0.1 -0.2 -0.3 -0.1
1955 -0.7 -0.6 -0.7 -0.8 -0.8 -0.7 -0.7 -0.7 -1.1 -1.4 -1.7 -1.5 1993 0.1 0.3 0.5 0.7 0.7 0.6 0.3 0.3 0.2 0.1 0.0 0.1
1956 -1.1 -0.8 -0.6 -0.5 -0.5 -0.5 -0.6 -0.6 -0.5 -0.4 -0.4 -0.4 1994 0.1 0.1 0.2 0.3 0.4 0.4 0.4 0.4 0.6 0.7 1.0 1.1
1957 -0.2 0.1 0.4 0.7 0.9 1.1 1.3 1.3 1.3 1.4 1.5 1.7 1995 1.0 0.7 0.5 0.3 0.1 0.0 -0.2 -0.5 -0.8 -1.0 -1.0 -1.0
1958 1.8 1.7 1.3 0.9 0.7 0.6 0.6 0.4 0.4 0.4 0.5 0.6 1996 -0.9 -0.8 -0.6 -0.4 -0.3 -0.3 -0.3 -0.3 -0.4 -0.4 -0.4 -0.5
1959 0.6 0.6 0.5 0.3 0.2 -0.1 -0.2 -0.3 -0.1 0.0 0.0 0.0 1997 -0.5 -0.4 -0.1 0.3 0.8 1.2 1.6 1.9 2.1 2.3 2.4 2.4
1960 -0.1 -0.1 -0.1 0.0 0.0 0.0 0.1 0.2 0.3 0.2 0.1 0.1 1998 2.2 1.9 1.4 1.0 0.5 -0.1 -0.8 -1.1 -1.3 -1.4 -1.5 -1.6
1961 0.0 0.0 0.0 0.1 0.2 0.3 0.1 -0.1 -0.3 -0.3 -0.2 -0.2 1999 -1.5 -1.3 -1.1 -1.0 -1.0 -1.0 -1.1 -1.1 -1.2 -1.3 -1.5 -1.7
1962 -0.2 -0.2 -0.2 -0.3 -0.3 -0.2 0.0 -0.1 -0.1 -0.2 -0.3 -0.4 2000 -1.7 -1.4 -1.1 -0.8 -0.7 -0.6 -0.6 -0.5 -0.5 -0.6 -0.7 -0.7
1963 -0.4 -0.2 0.2 0.3 0.3 0.5 0.9 1.1 1.2 1.3 1.4 1.3 2001 -0.7 -0.5 -0.4 -0.3 -0.3 -0.1 -0.1 -0.1 -0.2 -0.3 -0.3 -0.3
1964 1.1 0.6 0.1 -0.3 -0.6 -0.6 -0.6 -0.7 -0.8 -0.8 -0.8 -0.8 2002 -0.1 0.0 0.1 0.2 0.4 0.7 0.8 0.9 1.0 1.2 1.3 1.1
1965 -0.6 -0.3 -0.1 0.2 0.5 0.8 1.2 1.5 1.9 2.0 2.0 1.7 2003 0.9 0.6 0.4 0.0 -0.3 -0.2 0.1 0.2 0.3 0.3 0.4 0.4
1966 1.4 1.2 1.0 0.7 0.4 0.2 0.2 0.1 -0.1 -0.1 -0.2 -0.3 2004 0.4 0.3 0.2 0.2 0.2 0.3 0.5 0.6 0.7 0.7 0.7 0.7
1967 -0.4 -0.5 -0.5 -0.4 -0.2 0.0 0.0 -0.2 -0.3 -0.4 -0.3 -0.4 2005 0.6 0.6 0.4 0.4 0.3 0.1 -0.1 -0.1 -0.1 -0.3 -0.6 -0.8
1968 -0.6 -0.7 -0.6 -0.4 0.0 0.3 0.6 0.5 0.4 0.5 0.7 1.0 2006 -0.9 -0.8 -0.6 -0.4 -0.1 0.0 0.1 0.3 0.5 0.8 0.9 0.9
1969 1.1 1.1 0.9 0.8 0.6 0.4 0.4 0.5 0.8 0.9 0.8 0.6 2007 0.7 0.2 -0.1 -0.3 -0.4 -0.5 -0.6 -0.8 -1.1 -1.3 -1.5 -1.6
1970 0.5 0.3 0.3 0.2 0.0 -0.3 -0.6 -0.8 -0.8 -0.7 -0.9 -1.1 2008 -1.6 -1.5 -1.3 -1.0 -0.8 -0.6 -0.4 -0.2 -0.2 -0.4 -0.6 -0.7
1971 -1.4 -1.4 -1.1 -0.8 -0.7 -0.7 -0.8 -0.8 -0.8 -0.9 -1.0 -0.9 2009 -0.8 -0.8 -0.6 -0.3 0.0 0.3 0.5 0.6 0.7 1.0 1.4 1.6
1972 -0.7 -0.4 0.1 0.4 0.7 0.9 1.1 1.4 1.6 1.8 2.1 2.1 2010 1.5 1.2 0.8 0.4 -0.2 -0.7 -1.0 -1.3 -1.6 -1.6 -1.6 -1.6
1973 1.8 1.2 0.5 -0.1 -0.5 -0.9 -1.1 -1.3 -1.5 -1.7 -1.9 -2.0 2011 -1.4 -1.2 -0.9 -0.7 -0.6 -0.4 -0.5 -0.6 -0.8 -1.0 -1.1 -1.0
1974 -1.8 -1.6 -1.2 -1.0 -0.9 -0.8 -0.5 -0.4 -0.4 -0.6 -0.8 -0.6 2012 -0.9 -0.7 -0.6 -0.5 -0.3 0.0 0.2 0.4 0.4 0.3 0.1 -0.2
1975 -0.5 -0.6 -0.7 -0.7 -0.8 -1.0 -1.1 -1.2 -1.4 -1.4 -1.6 -1.7 2013 -0.4 -0.4 -0.3 -0.3 -0.4 -0.4 -0.4 -0.3 -0.3 -0.2 -0.2 -0.3
1976 -1.6 -1.2 -0.7 -0.5 -0.3 0.0 0.2 0.4 0.6 0.8 0.9 0.8 2014 -0.4 -0.5 -0.3 0.0 0.2 0.2 0.0 0.1 0.2 0.5 0.6 0.7
1977 0.7 0.6 0.3 0.2 0.2 0.3 0.4 0.4 0.6 0.7 0.8 0.8 2015 0.5 0.5 0.5 0.7 0.9 1.2 1.5 1.9 2.2 2.4 2.6 2.6
1978 0.7 0.4 0.1 -0.2 -0.3 -0.3 -0.4 -0.4 -0.4 -0.3 -0.1 0.0 2016 2.5 2.1 1.6 0.9 0.4 -0.1 -0.4 -0.5 -0.6 -0.7 -0.7 -0.6
1979 0.0 0.1 0.2 0.3 0.2 0.0 0.0 0.2 0.3 0.5 0.5 0.6 2017 -0.3 -0.2 0.1 0.2 0.3 0.3 0.1 -0.1 -0.4 -0.7 -0.8 -1.0
1980 0.6 0.5 0.3 0.4 0.5 0.5 0.3 0.0 -0.1 0.0 0.1 0.0 2018 -0.9 -0.9 -0.7 -0.5 -0.2 0.0 0.1 0.2 0.5 0.8 0.9 0.8
1981 -0.3 -0.5 -0.5 -0.4 -0.3 -0.3 -0.3 -0.2 -0.2 -0.1 -0.2 -0.1 2019 0.7 0.7 0.7 0.7 0.5 0.5 0.3 0.1 0.2 0.3 0.5 0.5
1982 0.0 0.1 0.2 0.5 0.7 0.7 0.8 1.1 1.6 2.0 2.2 2.2 2020 0.5 0.5 0.4 0.2 -0.1 -0.3 -0.4 -0.6 -0.9 -1.2 -1.3 -1.2
1983 2.2 1.9 1.5 1.3 1.1 0.7 0.3 -0.1 -0.5 -0.8 -1.0 -0.9 2021 -1.0 -0.9 -0.8 -0.7 -0.5 -0.4 -0.4 -0.5 -0.7 -0.8 -1.0 -1.0
1984 -0.6 -0.4 -0.3 -0.4 -0.5 -0.4 -0.3 -0.2 -0.2 -0.6 -0.9 -1.1 2022 -1.0 -0.9 -1.0 -1.1 -1.0 -0.9 -0.8 -0.9 -1.0 -1.0 -0.9 -0.8
1985 -1.0 -0.8 -0.8 -0.8 -0.8 -0.6 -0.5 -0.5 -0.4 -0.3 -0.3 -0.4 2023 -0.7 -0.4 -0.1 0.2 0.5 0.8 1.1 1.3 1.6 1.8 1.9 2.0
1986 -0.5 -0.5 -0.3 -0.2 -0.1 0.0 0.2 0.4 0.7 0.9 1.1 1.2 2024 1.8 1.5 1.1 0.7 0.4 0.2 0.1
1987 1.2 1.2 1.1 0.9 1.0 1.2 1.5 1.7 1.6 1.5 1.3 1.1 2025
Year DJF JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ Year DJF JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ

Source: NWS/CPC



I didn't stick to the weather.