1991-2020 Degrees Fahrenheit 1 70.6 72.4 -1.8 26 43 1967 1989 2003 2004 normal 2 67.5 69.4 -1.9 26 42 1975 2004 2003 2004 normal 3 64.6 66.4 -1.8 23 45 1975 2015 2003 2004 normal 1962,2003 4 62.8 64.0 -1.2 32 34 1975 2015 2001 2004 normal 1984,1988 5 61.3 62.4 -1.1 29 33 1975 2015 2002 2004 normal 1968,1990 6 61.0 62.6 -1.6 20 42 1973 2015 2001 2004 bottom-third 1988 7 62.8 64.7 -1.9 18 43 1973 2015 2001 2004 bottom-third 8 65.7 67.7 -2.0 18 43 1973 2015 2001 2004 bottom-third 2001 9 68.8 70.6 -1.8 18 43 1973 1996 2001 2004 bottom-third 1956,1970,2001 10 71.3 73.0 -1.7 20 41 1973 1996 2001 2004 bottom-third 1998,2001 11 72.8 74.4 -1.6 21 40 1973 2015 1998 2004 normal 12 73.6 74.9 -1.3 24 37 1973 2015 1991 2004 normal 1968,1984 18 70.0 70.8 -0.8 31 26 1976 2015 1994 2004 normal 24 74.6 74.9 -0.3 41 15 1973 2015,2016,2018 2002 2004 top-third 36 74.6 74.9 -0.3 35 16 1975 2017 2003 2004 top-third 2003 48 74.8 74.9 -0.1 35 11 1975,1976 2018 2004 2004 top-third 1998,2004 60 74.6 74.8 -0.2 29 12 1976,1977 2018 1998 2004 top-third 1998,2007