1991-2020 Degrees Fahrenheit 1 46.3 43.8 2.5 93 9 1983 2021 1998 1970 top-tenth 2 52.4 48.3 4.1 99 2 2000 2021 1998 1999 top-tenth 3 56.6 53.7 2.9 98 3 1976 2021 1998 1999 top-tenth 4 61.3 59.3 2.0 92 9 1976 2021 1997 1998 top-tenth 5 66.6 64.2 2.4 96 5 1976 2021 1997 1998 top-tenth 6 69.8 67.7 2.1 94 7 1976 1954 1997 1998 top-tenth 7 71.1 69.5 1.6 90 11 1976 2011 1997 1998 top-third 2015 8 71.0 69.8 1.2 89 12 1976 2011 1997 1998 top-third 1933,2021 9 70.1 69.0 1.1 88 13 1976 2011 1997 1998 top-third 2015,2016 10 68.3 67.6 0.7 86 15 1976 2011 1997 1998 top-third 1938,2001 11 66.8 65.6 1.2 91 9 1989 2011 1997 1998 top-tenth 1939 12 64.9 63.7 1.2 91 9 1979 2011 1997 1998 top-tenth 18 66.7 65.0 1.7 96 3 1973 2012 1998 1999 top-tenth 2016 24 65.0 63.7 1.3 97 2 1979 2012 1998 1999 top-tenth 2017 36 64.0 63.7 0.3 82 16 1970 2012 1998 1956 top-third 1935,1939,2014,2019 48 63.7 63.7 0.0 74 23 1979 2012,2013 1998 1957 top-third 1934,1936,1939,2021 60 63.5 63.6 -0.1 69 27 1979 2012 1998 1958 top-third