El Niño and La Niña Years and Intensities
Based on Oceanic Niño Index (ONI)
Jan Null, CCM

Updated thru October 2017
 
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 overlapping 3-month periods 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), Strong (1.5 to 1.9) and Very Strong (≥ 2.0) events.  For the purpose of this report for an event to be categorized as weak, moderate, strong or very strong it must have equaled or exceeded the threshold for at least 3 consecutive overlapping 3-month periods. [* Changed categories because of transition from ERSSTv4 to ERSSTv5 by CPC in the calculation of Sea Surface Temperatures (SST). 1950-51 removed from Weak La Niña]
El Niño La Niña
Weak - 10 Moderate - 7 Strong - 5 Very Strong - 3 Weak - 10 Moderate - 4 Strong - 7
1952-53 1951-52* 1957-58 1982-83 1954-55 1955-56 1973-74
1953-54 1963-64 1965-66 1997-98 1964-65 1970-71 1975-76
1958-59 1968-69* 1972-73 2015-16 1971-72 1995-96* 1988-89
1969-70 1986-87 1987-88*   1974-75 2011-12* 1998-99*
1976-77 1994-95* 1991-92*   1983-84   1999-00*
1977-78 2002-03     1984-85   2007-08*
1979-80 2009-10     2000-01 2010-11*
2004-05       2005-06*  
2006-07       2008-09    
2014-15*       2016-17    

 
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 Niño, VSE=Very Strong El Niño
WL=Weak La Niña, ML=Moderate La Niña, SL=Strong La Niña
ENSO                              
Type Season JJA JAS ASO SON OND NDJ DJF JFM FMA MAM AMJ MJJ
  1950 - 1951 -0.5 -0.4 -0.4 -0.4 -0.6 -0.8 -0.8 -0.5 -0.2 0.2 0.4 0.6
ME 1951 - 1952 0.7 0.9 1.0 1.2 1.0 0.8 0.5 0.4 0.3 0.3 0.2 0.0
WE 1952 - 1953 -0.1 0.0 0.2 0.1 0.0 0.1 0.4 0.6 0.6 0.7 0.8 0.8
WE 1953 - 1954 0.7 0.7 0.8 0.8 0.8 0.8 0.8 0.5 0.0 -0.4 -0.5 -0.5
WL 1954 - 1955 -0.6 -0.8 -0.9 -0.8 -0.7 -0.7 -0.7 -0.6 -0.7 -0.8 -0.8 -0.7
ML 1955 - 1956 -0.7 -0.7 -1.1 -1.4 -1.7 -1.5 -1.1 -0.8 -0.6 -0.5 -0.5 -0.5
  1956 - 1957 -0.6 -0.6 -0.5 -0.4 -0.4 -0.4 -0.2 0.1 0.4 0.7 0.9 1.1
SE 1957 - 1958 1.3 1.3 1.3 1.4 1.5 1.7 1.8 1.7 1.3 0.9 0.7 0.6
WE 1958 - 1959 0.6 0.4 0.4 0.4 0.5 0.6 0.6 0.6 0.5 0.3 0.2 -0.1
  1959 - 1960 -0.2 -0.3 -0.1 0.0 0.0 0.0 -0.1 -0.1 -0.1 0.0 0.0 0.0
  1960 - 1961 0.1 0.2 0.3 0.2 0.1 0.1 0.0 0.0 0.0 0.1 0.2 0.3
  1961 - 1962 0.1 -0.1 -0.3 -0.3 -0.2 -0.2 -0.2 -0.2 -0.2 -0.3 -0.3 -0.2
  1962 - 1963 0.0 -0.1 -0.1 -0.2 -0.3 -0.4 -0.4 -0.2 0.2 0.3 0.3 0.5
ME 1963 - 1964 0.9 1.1 1.2 1.3 1.4 1.3 1.1 0.6 0.1 -0.3 -0.6 -0.6
WL 1964 - 1965 -0.6 -0.7 -0.8 -0.8 -0.8 -0.8 -0.6 -0.3 -0.1 0.2 0.5 0.8
SE 1965 - 1966 1.2 1.5 1.9 2.0 2.0 1.7 1.4 1.2 1.0 0.7 0.4 0.2
  1966 - 1967 0.2 0.1 -0.1 -0.1 -0.2 -0.3 -0.4 -0.5 -0.5 -0.4 -0.2 0.0
  1967 - 1968 0.0 -0.2 -0.3 -0.4 -0.3 -0.4 -0.6 -0.7 -0.6 -0.4 0.0 0.3
ME 1968 - 1969 0.6 0.5 0.4 0.5 0.7 1.0 1.1 1.1 0.9 0.8 0.6 0.4
WE 1969 - 1970 0.4 0.5 0.8 0.9 0.8 0.6 0.5 0.3 0.3 0.2 0.0 -0.3
ML 1970 - 1971 -0.6 -0.8 -0.8 -0.7 -0.9 -1.1 -1.4 -1.4 -1.1 -0.8 -0.7 -0.7
WL 1971 - 1972 -0.8 -0.8 -0.8 -0.9 -1.0 -0.9 -0.7 -0.4 0.1 0.4 0.7 0.9
SE 1972 - 1973 1.1 1.4 1.6 1.8 2.1 2.1 1.8 1.2 0.5 -0.1 -0.5 -0.9
SL 1973 - 1974 -1.1 -1.3 -1.5 -1.7 -1.9 -2.0 -1.8 -1.6 -1.2 -1.0 -0.9 -0.8
WL 1974 - 1975 -0.5 -0.4 -0.4 -0.6 -0.8 -0.6 -0.5 -0.6 -0.7 -0.7 -0.8 -1.0
SL 1975 - 1976 -1.1 -1.2 -1.4 -1.4 -1.6 -1.7 -1.6 -1.2 -0.7 -0.5 -0.3 0.0
WE 1976 - 1977 0.2 0.4 0.6 0.8 0.9 0.8 0.7 0.6 0.3 0.2 0.2 0.3
WE 1977 - 1978 0.4 0.4 0.6 0.7 0.8 0.8 0.7 0.4 0.1 -0.2 -0.3 -0.3
  1978 - 1979 -0.4 -0.4 -0.4 -0.3 -0.1 0.0 0.0 0.1 0.2 0.3 0.2 0.0
WE 1979 - 1980 0.0 0.2 0.3 0.5 0.5 0.6 0.6 0.5 0.3 0.4 0.5 0.5
  1980 - 1981 0.3 0.0 -0.1 0.0 0.1 0.0 -0.3 -0.5 -0.5 -0.4 -0.3 -0.3
  1981 - 1982 -0.3 -0.2 -0.2 -0.1 -0.2 -0.1 0.0 0.1 0.2 0.5 0.7 0.7
VSE 1982 - 1983 0.8 1.1 1.6 2.0 2.2 2.2 2.2 1.9 1.5 1.3 1.1 0.7
WL 1983 - 1984 0.3 -0.1 -0.5 -0.8 -1.0 -0.9 -0.6 -0.4 -0.3 -0.4 -0.5 -0.4
WL 1984 - 1985 -0.3 -0.2 -0.2 -0.6 -0.9 -1.1 -1.0 -0.8 -0.8 -0.8 -0.8 -0.6
  1985 - 1986 -0.5 -0.5 -0.4 -0.3 -0.3 -0.4 -0.5 -0.5 -0.3 -0.2 -0.1 0.0
ME 1986 - 1987 0.2 0.4 0.7 0.9 1.1 1.2 1.2 1.2 1.1 0.9 1.0 1.2
SE 1987 - 1988 1.5 1.7 1.6 1.5 1.3 1.1 0.8 0.5 0.1 -0.3 -0.9 -1.3
SL 1988 - 1989 -1.3 -1.1 -1.2 -1.5 -1.8 -1.8 -1.7 -1.4 -1.1 -0.8 -0.6 -0.4
  1989 - 1990 -0.3 -0.3 -0.2 -0.2 -0.2 -0.1 0.1 0.2 0.3 0.3 0.3 0.3
  1990 - 1991 0.3 0.4 0.4 0.3 0.4 0.4 0.4 0.3 0.2 0.3 0.5 0.6
SE 1991 - 1992 0.7 0.6 0.6 0.8 1.2 1.5 1.7 1.6 1.5 1.3 1.1 0.7
  1992 - 1993 0.4 0.1 -0.1 -0.2 -0.3 -0.1 0.1 0.3 0.5 0.7 0.7 0.6
  1993 - 1994 0.3 0.3 0.2 0.1 0.0 0.1 0.1 0.1 0.2 0.3 0.4 0.4
ME 1994 - 1995 0.4 0.4 0.6 0.7 1.0 1.1 1.0 0.7 0.5 0.3 0.1 0.0
ML 1995 - 1996 -0.2 -0.5 -0.8 -1.0 -1.0 -1.0 -0.9 -0.8 -0.6 -0.4 -0.3 -0.3
  1996 - 1997 -0.3 -0.3 -0.4 -0.4 -0.4 -0.5 -0.5 -0.4 -0.1 0.3 0.8 1.2
VSE 1997 - 1998 1.6 1.9 2.1 2.3 2.4 2.4 2.2 1.9 1.4 1.0 0.5 -0.1
SL 1998 - 1999 -0.8 -1.1 -1.3 -1.4 -1.5 -1.6 -1.5 -1.3 -1.1 -1.0 -1.0 -1.0
SL 1999 - 2000 -1.1 -1.1 -1.2 -1.3 -1.5 -1.7 -1.7 -1.4 -1.1 -0.8 -0.7 -0.6
WL 2000 - 2001 -0.6 -0.5 -0.5 -0.6 -0.7 -0.7 -0.7 -0.5 -0.4 -0.3 -0.3 -0.1
  2001 - 2002 -0.1 -0.1 -0.2 -0.3 -0.3 -0.3 -0.1 0.0 0.1 0.2 0.4 0.7
ME 2002 - 2003 0.8 0.9 1.0 1.2 1.3 1.1 0.9 0.6 0.4 0.0 -0.3 -0.2
  2003 - 2004 0.1 0.2 0.3 0.3 0.4 0.4 0.4 0.3 0.2 0.2 0.2 0.3
WE 2004 - 2005 0.5 0.6 0.7 0.7 0.7 0.7 0.6 0.6 0.4 0.4 0.3 0.1
WL 2005 - 2006 -0.1 -0.1 -0.1 -0.3 -0.6 -0.8 -0.8 -0.7 -0.5 -0.3 0.0 0.0
WE 2006 - 2007 0.1 0.3 0.5 0.7 0.9 0.9 0.7 0.3 0.0 -0.2 -0.3 -0.4
SL 2007 - 2008 -0.5 -0.8 -1.1 -1.4 -1.5 -1.6 -1.6 -1.4 -1.2 -0.9 -0.8 -0.5
WL 2008 - 2009 -0.4 -0.3 -0.3 -0.4 -0.6 -0.7 -0.8 -0.7 -0.5 -0.2 0.1 0.4
ME 2009 - 2010 0.5 0.5 0.7 1.0 1.3 1.6 1.5 1.3 0.9 0.4 -0.1 -0.6
SL 2010 - 2011 -1.0 -1.4 -1.6 -1.7 -1.7 -1.6 -1.4 -1.1 -0.8 -0.6 -0.5 -0.4
ML 2011 - 2012 -0.5 -0.7 -0.9 -1.1 -1.1 -1.0 -0.8 -0.6 -0.5 -0.4 -0.2 0.1
  2012 - 2013 0.3 0.3 0.3 0.2 0.0 -0.2 -0.4 -0.3 -0.2 -0.2 -0.3 -0.3
  2013 - 2014 -0.4 -0.4 -0.3 -0.2 -0.2 -0.3 -0.4 -0.4 -0.2 0.1 0.3 0.2
WE 2014 - 2015 0.1 0.0 0.2 0.4 0.6 0.7 0.6 0.6 0.6 0.8 1.0 1.2
VSE 2015 - 2016 1.5 1.8 2.1 2.4 2.5 2.6 2.5 2.2 1.7 1.0 0.5 0.0
WL 2016 - 2017 -0.3 -0.6 -0.7 -0.7 -0.7 -0.6 -0.3 -0.1 0.1 0.3 0.4 0.4
  2017 - 2018 0.1 -0.1 -0.4                  
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