1991-2020 Degrees Fahrenheit 1 54.2 50.0 4.2 71 5 1976 1985 1998 1985 top-tenth 2 57.2 55.7 1.5 63 13 1976 2016 1997 1998 top-third 3 62.1 61.4 0.7 60 16 1976 2016 1997 1998 top-third 1990 4 66.5 65.9 0.6 61 15 1976 2016 1997 1998 top-third 1971,2022 5 69.6 68.8 0.8 63 13 1976 2016 1997 1998 top-third 1983,1985 6 70.8 70.1 0.7 63 13 1976 2016 1997 1998 top-third 7 70.4 70.0 0.4 63 13 1976 2016 1997 1998 top-third 1954 8 69.4 68.8 0.6 64 12 1976 2016 1997 1998 top-third 2006 9 66.8 66.8 0.0 54 22 1976 2016 1997 1998 top-third 1948,1955,2000 10 64.7 64.4 0.3 61 15 1960 2016 1997 1998 top-third 1977,2006,2021 11 62.7 62.1 0.6 62 14 1979 2016 1997 1998 top-third 1953 12 61.1 60.5 0.6 64 10 1979 2016 1997 1998 top-third 2005 18 64.6 63.7 0.9 66 8 1968,1977 2017 1998 1999 top-third 24 61.4 60.6 0.8 63 9 1979 2017 1998 1999 top-third 36 60.6 60.6 0.0 54 16 1980 2018 1998 1954 top-third 48 59.9 60.6 -0.7 42 26 1979 2019 1998 1957 normal 60 59.8 60.5 -0.7 39 27 1980 2020 1993 1957 normal 1954