1991-2020 Degrees Fahrenheit 1 43.7 43.1 0.6 73 56 1994 1926 2015 2017 normal 2 48.7 48.7 0.0 75 52 1994 1933 2013 2017 normal 1900,1940,1944,1954 3 55.1 54.6 0.5 102 25 1982 2012 2013 2017 top-third 4 60.6 59.6 1.0 110 16 1982 2012 2015 2017 top-third 2015 5 64.8 62.9 1.9 119 7 1982 2012 2016 2017 top-tenth 6 65.8 63.9 1.9 120 6 1982 2021 2016 2017 top-tenth 7 65.1 63.2 1.9 120 5 1916 2021 2016 2017 top-tenth 8 63.6 61.7 1.9 120 5 1896 2021 2016 2017 top-tenth 9 61.2 59.9 1.3 114 11 1912 2014 2013 2017 top-tenth 10 58.8 57.9 0.9 112 12 1897 2014 2013 2017 top-tenth 1988 11 57.3 56.0 1.3 113 11 1897 2014 2013 2017 top-tenth 12 55.5 54.2 1.3 114 10 1897 2015 2013 2017 top-tenth 1992 18 59.1 57.4 1.7 116 5 1898 2015 2017 2015 top-tenth 24 55.7 54.2 1.5 114 6 1898 2015 2014 2017 top-tenth 36 55.7 54.1 1.6 113 4 1898 2016,2017 2015 2017 top-tenth 2015 48 55.9 54.1 1.8 112 2 1913 2017 2016 2017 top-tenth 60 55.9 54.1 1.8 111 1 1975 2018 2017 2018 highest