Rainfall
Season

(Note: Each rainfall
season ends in the year
listed below but starts
the previous fall.)
Three-Month Running Average
Oceanic Nino Index (ONI)
(Oct-Apr)
"SON" is the Sept., Oct., and Nov. average;
"OND" is the Oct., Nov., and Dec. average, etc.

SON

OND

NDJ

DJF

JFM

FMA

MAM

1951 -0.9 -0.9 -1.0 -1.0 -0.9 -0.6 -0.3
1952 0.8 0.7 0.6 0.3 0.1 0.1 0.2
1953 -0.2 -0.1 0.0 0.2 0.4 0.5 0.5
1954 0.4 0.4 0.4 0.5 0.3 -0.1 -0.5
1955 -1.1 -1.1 -1.1 -1.0 -0.9 -0.9 -1.0
1956 -1.8 -2.0 -1.9 -1.3 -0.9 -0.7 -0.6
1957 -0.9 -0.9 -0.8 -0.5 -0.1 0.3 0.6
1958 1.0 1.2 1.5 1.7 1.5 1.2 0.8
1959 0.0 0.2 0.4 0.4 0.5 0.4 0.2
1960 -0.3 -0.2 -0.2 -0.3 -0.3 -0.3 -0.2
1961 -0.2 -0.2 -0.2 -0.2 -0.2 -0.2 -0.1
1962 -0.6 -0.5 -0.4 -0.4 -0.4 -0.4 -0.5
1963 -0.6 -0.7 -0.7 -0.6 -0.3 0.0 0.1
1964 0.9 1.0 1.0 0.8 0.4 -0.1 -0.5
1965 -1.2 -1.2 -1.0 -0.8 -0.4 -0.2 0.0
1966 1.5 1.6 1.5 1.2 1.0 0.8 0.5
1967 -0.2 -0.3 -0.3 -0.4 -0.4 -0.6 -0.5
1968 -0.5 -0.4 -0.5 -0.7 -0.9 -0.8 -0.7
1969 0.4 0.7 0.9 1.0 1.0 0.9 0.7
1970 0.7 0.8 0.7 0.5 0.3 0.2 0.1
1971 -0.8 -0.9 -1.1 -1.3 -1.3 -1.1 -0.9
1972 -0.9 -1.0 -0.9 -0.7 -0.4 0.0 0.2
1973 1.8 2.0 2.1 1.8 1.2 0.5 -0.1
1974 -1.7 -2.0 -2.1 -1.9 -1.7 -1.3 -1.1
1975 -0.7 -0.9 -0.7 -0.6 -0.6 -0.7 -0.8
1976 -1.6 -1.7 -1.7 -1.6 -1.2 -0.8 -0.6
1977 0.7 0.8 0.7 0.6 0.5 0.2 0.2
1978 0.6 0.7 0.7 0.7 0.4 0.0 -0.3
1979 -0.3 -0.2 -0.1 -0.1 0.0 0.1 0.1
1980 0.4 0.5 0.5 0.5 0.3 0.2 0.2
1981 -0.1 0.0 -0.1 -0.3 -0.5 -0.5 -0.4
1982 -0.2 -0.1 -0.1 0.0 0.1 0.1 0.3
1983 1.9 2.2 2.3 2.3 2.0 1.5 1.2
1984 -0.8 -0.9 -0.7 -0.4 -0.2 -0.2 -0.3
1985 -0.6 -0.9 -1.1 -0.9 -0.8 -0.7 -0.7
1986 -0.4 -0.3 -0.4 -0.5 -0.4 -0.2 -0.2
1987 0.9 1.1 1.2 1.2 1.3 1.2 1.1
1988 1.5 1.3 1.1 0.7 0.5 0.1 -0.2
1989 -1.6 -1.9 -1.9 -1.7 -1.5 -1.1 -0.8
1990 -0.3 -0.2 -0.1 0.1 0.2 0.2 0.2
1991 0.3 0.3 0.4 0.4 0.3 0.3 0.4
1992 1.0 1.4 1.6 1.8 1.6 1.5 1.4
1993 -0.1 0.0 0.2 0.3 0.4 0.6 0.7
1994 0.4 0.3 0.2 0.2 0.2 0.3 0.4
1995 0.9 1.2 1.3 1.2 0.9 0.7 0.4
1996 -0.6 -0.7 -0.7 -0.7 -0.7 -0.5 -0.3
1997 -0.2 -0.3 -0.4 -0.4 -0.3 0.0 0.4
1998 2.4 2.5 2.5 2.3 1.9 1.5 1.0
1999 -1.1 -1.3 -1.4 -1.4 -1.2 -0.9 -0.8
2000 -1.1 -1.3 -1.6 -1.6 -1.4 -1.0 -0.8
2001 -0.5 -0.6 -0.7 -0.6 -0.5 -0.4 -0.2
2002 0.0 -0.1 -0.1 -0.1 0.1 0.2 0.4
2003 1.3 1.5 1.4 1.2 0.9 0.5 0.1
2004 0.5 0.6 0.4 0.4 0.3 0.2 0.2
2005 0.8 0.8 0.8 0.7 0.5 0.4 0.4
2006 -0.1 -0.4 -0.7 -0.7 -0.6 -0.4 -0.1
2007 0.9 1.1 1.1 0.8 0.4 0.1 -0.1
2008 -1.0 -1.1 -1.3 -1.4 -1.4 -1.1 -0.8
2009 0.0 -0.3 -0.6 -0.8 -0.7 -0.5 -0.1
2010 1.2 1.5 1.8 1.7 1.5 1.2 0.8
2011 -1.5 -1.5 -1.5 -1.4 -1.3 -1.0 -0.7
2012 -0.8 -1.0 -1.0 -0.9 -0.7