1991-2020 Degrees Fahrenheit 1 85.5 88.7 -3.2 9 59 1965 2021 1991 1996 bottom-third 2 85.7 84.3 1.4 56 12 1965 2001,2006 1995 1996 top-third 3 81.1 80.3 0.8 48 20 1967 2000 1995 1996 top-third 1958,1987 4 78.3 76.8 1.5 58 10 1975 2004,2013 1995 1996 top-third 5 74.5 73.5 1.0 58 10 1975 2014,2015,2016,2017 1995 1996 top-third 2012,2022 6 71.8 70.7 1.1 57 9 1955,1975 2014 1995 1996 top-third 2004,2012 7 69.5 68.7 0.8 51 11 1975 2015 1995 1996 top-third 8 68.8 68.1 0.7 53 9 1975 1996 1995 1996 top-third 1978,2016 9 69.6 69.1 0.5 46 15 1975 1996,2015 1995 1996 top-third 1992 10 71.2 71.0 0.2 44 17 1973 1996 1995 1996 top-third 1959,1984 11 73.4 73.1 0.3 48 13 1973 1996 1995 1996 top-third 1978,1981,1992 12 75.3 74.9 0.4 48 13 1973,1975 1996 1995 1996 top-third 1981 18 74.4 73.5 0.9 53 7 1956,1976,1983 2015 1995 1996 top-third 24 76.1 74.9 1.2 53 3 1973 2018 1996 1997 top-tenth 2017 36 75.2 74.9 0.3 43 8 1975 2017,2018 1996 1997 top-third 48 75.0 74.9 0.1 36 10 1975 2018 1996 1997 top-third 60 74.8 74.8 0.0 31 10 1975,1977 2018 1996 1997 top-third