1991-2020 Degrees Fahrenheit 1 72.4 72.4 0.0 39 30 1967 1989 1958 1960 normal 2 68.0 69.4 -1.4 31 37 1975 2004 1958 1960 normal 1995,2020 3 65.6 66.4 -0.8 39 29 1975 2015 1960 1959 normal 2002 4 63.6 64.0 -0.4 45 21 1975 2015 1960 1959 top-third 1968,1994 5 61.5 62.4 -0.9 33 29 1975 2015 1960 1959 normal 6 61.6 62.6 -1.0 29 33 1973 2015 1960 1959 normal 2019 7 63.5 64.7 -1.2 30 31 1973 2015 1960 1959 normal 8 66.6 67.7 -1.1 30 31 1973 2015 1960 1959 normal 9 69.5 70.6 -1.1 27 34 1973 1996 1960 1959 normal 1982 10 72.1 73.0 -0.9 34 27 1973 1996 1960 1959 normal 1990,1995 11 73.9 74.4 -0.5 38 23 1973 2015 1960 1959 normal 1995 12 74.3 74.9 -0.6 41 20 1973 2015 1960 1959 top-third 1995,2006 18 69.9 70.8 -0.9 30 27 1976 2015 1960 1960 normal 1960,2006 24 73.9 74.9 -1.0 29 27 1973 2015,2016,2018 1959 1960 normal 1959,1989,2006 36 74.3 74.9 -0.6 32 19 1975 2017 1960 1961 normal 2007 48 73.9 74.9 -1.0 25 21 1975,1976 2018 1960 1961 normal 1994 60 73.8 74.8 -1.0 21 20 1976,1977 2018 1960 1961 normal