El Niño and La Niña Years and Intensities
 Based on Oceanic Niño Index (ONI)
 Jan Null, CCM
Updated March 2010
 
The Oceanic Niño Index (ONI) has become the de-facto standard that NOAA uses for identifying El Niño (warm) and La Niña (cool) events in the tropical Pacific.  It is the running 3-month mean SST anomaly for the Niño 3.4 region (i.e., 5oN-5oS, 120o-170oW).  Events are defined as 5 consecutive months at or above the +0.5o anomaly for warm (El Niño) events and at or below the -0.5 anomaly for cold (La Niña) events.  The threshold is further broken down into Weak (with a 0.5 to 0.9 SST anomaly), Moderate (1.0 to 1.4) and Strong (≥ 1.5) events.  For the purpose of this report for an event to be weak, moderate or strong it much have equaled or exceeded the threshold for at least 3 months.
El Niño La Niña
Weak Mod Strong Weak Mod Strong
1951 1986 1957 1950 1954 1955
1963 1987 1965 1956 1964 1973
1968 1994 1972 1962 1970 1975
1969 2002 1982 1967 1998 1988
1976   1991 1971 1999  
1977   1997 1974 2007  
2004 2009 1984  
2006 1995  
      2000    
 
 
Running 3-Month Mean ONI values
http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml
WE=Weak El Niño, ME=Moderate El Niño, SE=Strong El Niñ
WL=Weak La Niña, ML=Moderate La Niña, SL=La Niña
ENSO Type Season
1949 1950 JJA JAS ASO SON OND NDJ DJF JFM FMA MAM AMJ MJJ
WL 1950 1951 -0.8 -0.8 -0.8 -0.9 -0.9 -1.0 -1.0 -0.9 -0.6 -0.3 -0.2 0.2
WE 1951 1952 0.4 0.7 0.7 0.8 0.7 0.6 0.3 0.1 0.1 0.2 0.1 -0.1
1952 1953 -0.3 -0.3 -0.2 -0.2 -0.1 0.0 0.2 0.4 0.5 0.5 0.5 0.5
1953 1954 0.4 0.4 0.4 0.4 0.4 0.4 0.5 0.3 -0.1 -0.5 -0.7 -0.7
ML 1954 1955 -0.8 -1.0 -1.2 -1.1 -1.1 -1.1 -1.0 -0.9 -0.9 -1.0 -1.0 -1.0
SL 1955 1956 -1.0 -1.0 -1.4 -1.8 -2.0 -1.9 -1.3 -0.9 -0.7 -0.6 -0.6 -0.6
WL 1956 1957 -0.7 -0.8 -0.8 -0.9 -0.9 -0.8 -0.5 -0.1 0.3 0.6 0.7 0.9
SE 1957 1958 0.9 0.9 0.9 1.0 1.2 1.5 1.7 1.5 1.2 0.8 0.6 0.5
1958 1959 0.3 0.1 0.0 0.0 0.2 0.4 0.4 0.5 0.4 0.2 0.0 -0.2
1959 1960 -0.4 -0.5 -0.4 -0.3 -0.2 -0.2 -0.3 -0.3 -0.3 -0.2 -0.2 -0.2
1960 1961 -0.1 0.0 -0.1 -0.2 -0.2 -0.2 -0.2 -0.2 -0.2 -0.1 0.1 0.2
1961 1962 0.0 -0.3 -0.6 -0.6 -0.5 -0.4 -0.4 -0.4 -0.4 -0.5 -0.4 -0.4
WL 1962 1963 -0.3 -0.3 -0.5 -0.6 -0.7 -0.7 -0.6 -0.3 0.0 0.1 0.1 0.3
WE 1963 1964 0.6 0.8 0.9 0.9 1.0 1.0 0.8 0.4 -0.1 -0.5 -0.8 -0.8
ML 1964 1965 -0.9 -1.0 -1.1 -1.2 -1.2 -1.0 -0.8 -0.4 -0.2 0.0 0.3 0.6
SE 1965 1966 1.0 1.2 1.4 1.5 1.6 1.5 1.2 1.0 0.8 0.5 0.2 0.2
1966 1967 0.2 0.0 -0.2 -0.2 -0.3 -0.3 -0.4 -0.4 -0.6 -0.5 -0.3 0.0
WL 1967 1968 0.0 -0.2 -0.4 -0.5 -0.4 -0.5 -0.7 -0.9 -0.8 -0.7 -0.3 0.0
WE 1968 1969 0.3 0.4 0.3 0.4 0.7 0.9 1.0 1.0 0.9 0.7 0.6 0.5
WE 1969 1970 0.4 0.4 0.6 0.7 0.8 0.7 0.5 0.3 0.2 0.1 0.0 -0.3
ML 1970 1971 -0.6 -0.8 -0.9 -0.8 -0.9 -1.1 -1.3 -1.3 -1.1 -0.9 -0.8 -0.8
WL 1971 1972 -0.8 -0.8 -0.8 -0.9 -1.0 -0.9 -0.7 -0.4 0.0 0.2 0.5 0.8
SE 1972 1973 1.0 1.3 1.5 1.8 2.0 2.1 1.8 1.2 0.5 -0.1 -0.6 -0.9
SL 1973 1974 -1.1 -1.3 -1.4 -1.7 -2.0 -2.1 -1.9 -1.7 -1.3 -1.1 -0.9 -0.8
WL 1974 1975 -0.6 -0.5 -0.5 -0.7 -0.9 -0.7 -0.6 -0.6 -0.7 -0.8 -0.9 -1.1
SL 1975 1976 -1.2 -1.3 -1.5 -1.6 -1.7 -1.7 -1.6 -1.2 -0.8 -0.6 -0.5 -0.2
WE 1976 1977 0.1 0.3 0.5 0.7 0.8 0.7 0.6 0.5 0.2 0.2 0.2 0.4
WE 1977 1978 0.4 0.4 0.5 0.6 0.7 0.7 0.7 0.4 0.0 -0.3 -0.4 -0.4
1978 1979 -0.4 -0.4 -0.4 -0.3 -0.2 -0.1 -0.1 0.0 0.1 0.1 0.1 -0.1
1979 1980 0.0 0.1 0.3 0.4 0.5 0.5 0.5 0.3 0.2 0.2 0.3 0.3
1980 1981 0.2 0.0 -0.1 -0.1 0.0 -0.1 -0.3 -0.5 -0.5 -0.4 -0.3 -0.3
1981 1982 -0.4 -0.4 -0.3 -0.2 -0.1 -0.1 0.0 0.1 0.1 0.3 0.6 0.7
SE 1982 1983 0.7 1.0 1.5 1.9 2.2 2.3 2.3 2.0 1.5 1.2 1.0 0.6
1983 1984 0.2 -0.2 -0.6 -0.8 -0.9 -0.7 -0.4 -0.2 -0.2 -0.3 -0.5 -0.4
WL 1984 1985 -0.3 -0.2 -0.3 -0.6 -0.9 -1.1 -0.9 -0.8 -0.7 -0.7 -0.7 -0.6
1985 1986 -0.5 -0.5 -0.5 -0.4 -0.3 -0.4 -0.5 -0.4 -0.2 -0.2 -0.1 0.0
ME 1986 1987 0.3 0.5 0.7 0.9 1.1 1.2 1.2 1.3 1.2 1.1 1.0 1.2
ME 1987 1988 1.4 1.6 1.6 1.5 1.3 1.1 0.7 0.5 0.1 -0.2 -0.7 -1.2
SL 1988 1989 -1.3 -1.2 -1.3 -1.6 -1.9 -1.9 -1.7 -1.5 -1.1 -0.8 -0.6 -0.4
1989 1990 -0.3 -0.3 -0.3 -0.3 -0.2 -0.1 0.1 0.2 0.2 0.2 0.2 0.2
1990 1991 0.3 0.3 0.3 0.3 0.3 0.4 0.4 0.3 0.3 0.4 0.6 0.8
SE 1991 1992 1.0 0.9 0.9 1.0 1.4 1.6 1.8 1.6 1.5 1.4 1.2 0.8
1992 1993 0.5 0.2 0.0 -0.1 0.0 0.2 0.3 0.4 0.6 0.7 0.8 0.7
1993 1994 0.4 0.4 0.4 0.4 0.3 0.2 0.2 0.2 0.3 0.4 0.5 0.5
ME 1994 1995 0.6 0.6 0.7 0.9 1.2 1.3 1.2 0.9 0.7 0.4 0.3 0.2
WL 1995 1996 0.0 -0.2 -0.5 -0.6 -0.7 -0.7 -0.7 -0.7 -0.5 -0.3 -0.1 -0.1
1996 1997 0.0 -0.1 -0.1 -0.2 -0.3 -0.4 -0.4 -0.3 0.0 0.4 0.8 1.3
SE 1997 1998 1.7 2.0 2.2 2.4 2.5 2.5 2.3 1.9 1.5 1.0 0.5 0.0
ML 1998 1999 -0.5 -0.8 -1.0 -1.1 -1.3 -1.4 -1.4 -1.2 -0.9 -0.8 -0.8 -0.8
ML 1999 2000 -0.9 -0.9 -1.0 -1.1 -1.3 -1.6 -1.6 -1.4 -1.0 -0.8 -0.6 -0.5
WL 2000 2001 -0.4 -0.4 -0.4 -0.5 -0.6 -0.7 -0.6 -0.5 -0.4 -0.2 -0.1 0.1
2001 2002 0.2 0.2 0.1 0.0 -0.1 -0.1 -0.1 0.1 0.2 0.4 0.7 0.8
ME 2002 2003 0.9 1.0 1.1 1.3 1.5 1.4 1.2 0.9 0.5 0.1 -0.1 0.1
2003 2004 0.4 0.5 0.6 0.5 0.6 0.4 0.4 0.3 0.2 0.2 0.3 0.5
WE 2004 2005 0.7 0.8 0.9 0.8 0.8 0.8 0.7 0.5 0.4 0.4 0.4 0.4
2005 2006 0.4 0.3 0.2 -0.1 -0.4 -0.7 -0.7 -0.6 -0.4 -0.1 0.1 0.2
WE 2006 2007 0.3 0.5 0.6 0.9 1.1 1.1 0.8 0.4 0.1 -0.1 -0.1 -0.1
ML 2007 2008 -0.1 -0.4 -0.7 -1.0 -1.1 -1.3 -1.4 -1.4 -1.1 -0.8 -0.6 -0.4
2008 2009 -0.1 0.0 0.0 0.0 -0.3 -0.6 -0.8 -0.7 -0.5 -0.1 0.2 0.6
SE 2009 2010 0.7 0.8 0.9 1.2 1.5 1.8 1.7          
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