El Niño Southern Oscillation (ENSO)

Past ENSO Events


What years are ENSO years?

Because ENSO events differ in their strength, coverage, and seasonality, there isn't unanimous agreement on what constitutes and ENSO event. But, there are broad agreements and you can find some of the lists researchers have used along with how they chose those years. The list in the right column represents ENSO years based on PSD's Extended Multivariate ENSO Index (MEI.ext).

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Animations of Selected Past Events

1982–1983 El Niño

2010–2011 La Niña

1991–1992 El Niño

1988–1989 La Niña

1997–1998 El Niño

1999–2000 La Niña


Past ENSO Years

El NiñoNeutralLa Niña
1897
1900
1903
1906
1915
1919
1926
1931
1941
1942
1958
1966
1973
1978
1980
1983
1987
1988
1992
1995
1998
2003
2007
2010
1896
1898-1899
1901-1902
1905
1907-1908
1912-1914
1916
1920-1924
1927-1930
1932-1933
1935-1938
1940
1944-1949
1952-1954
1957
1959-1961
1963-1965
1967-1970
1972
1975
1977
1979
1981-1982
1984-1986
1990-1991
1993-1994
1996-1997
2001-2002
2004-2006
2009
2013-2014
1904
1909
1910
1911
1917
1918
1925
1934
1939
1943
1950
1951
1955
1956
1962
1971
1974
1976
1989
1999
2000
2008
2011
2012
Years are determined from Dec-Jan-Feb (DJF) values of the PSD MEI.ext index. ENSO events are most clearly defined in northern winter (DJF), both in terms of impacts and robustness with regard to the ENSO index used. Other seasons have impacts, too, but do not necessarily match the winter seasons.

Comparison of Timeseries of Historic Events

MEI of 7 strongest El Nino events since 1950 vs. 2009-10
MEI of 7 strongest La Nina events since 1949