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

Updated thru Jul-Aug-Sep 2021
 
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.
El Niño - 26 La Niña - 23
Weak - 11 Moderate - 7 Strong - 5 Very Strong - 3 Weak - 11 Moderate - 5 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 2020-21 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    
2018-19       2017-18    

Graph - Oceanic Niño Index (ONI) 1950-present
Graph - Ocean Niño Index (ONI) 1950-1989

Running 3-Month Mean ONI values
https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php
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 1.9 2.2 2.4 2.6 2.6 2.5 2.1 1.6 0.9 0.4 -0.1
WL 2016-2017 -0.4 -0.5 -0.6 -0.7 -0.7 -0.6 -0.3 -0.2 0.1 0.2 0.3 0.3
WL 2017-2018 0.1 -0.1 -0.4 -0.7 -0.8 -1.0 -0.9 -0.9 -0.7 -0.5 -0.2 0.0
WE 2018-2019 0.1 0.2 0.5 0.8 0.9 0.8 0.8 0.7 0.7 0.7 0.5 0.5
  2019-2020 0.3 0.1 0.2 0.4 0.5 0.6 0.5 0.5 0.4 0.2 -0.1 -0.3
ML 2020-2021 -0.4 -0.6 -0.9 -1.2 -1.3 -1.2 -1.1 -0.9 -0.8 -0.7 -0.5 -0.4
2021-2022 -0.4 -0.5                    
ENSO Type Season JJA JAS ASO SON OND NDJ DJF JFM FMA MAM AMJ MJJ
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