1991-2020 Degrees Fahrenheit 1 68.8 69.2 -0.4 91 39 1931 2006 2018 2017 top-third 2 64.8 65.8 -1.0 75 55 1915 2006 2014 2018 normal 1909,1936,1956,1994 3 62.5 62.6 -0.1 102 28 1958 2017 2015 2018 top-third 1911,1991 4 59.9 59.9 0.0 98 32 1978 2017 2015 2018 top-third 5 58.8 58.6 0.2 104 25 1915 2017 2015 2018 top-third 1921 6 58.4 58.9 -0.5 93 36 1912 2017 2015 2018 top-third 1976,1989 7 60.1 60.6 -0.5 96 33 1977 2017 2015 2018 top-third 1950,1957 8 62.5 63.0 -0.5 97 32 1977 2017 2015 2018 top-third 1950 9 65.2 65.4 -0.2 104 25 1977 2017 2015 2018 top-third 1986,2015 10 67.3 67.4 -0.1 110 19 1977 2017 2015 2018 top-third 1934 11 69.1 68.7 0.4 115 14 1977 2017 2015 2018 top-third 2011 12 70.0 69.3 0.7 116 13 1977 2017,2023 2015 2018 top-tenth 2013 18 66.9 65.8 1.1 119 9 1913 2017 2016 2018 top-tenth 2013 24 70.3 69.3 1.0 118 10 1978 2017 2016 2018 top-tenth 36 71.0 69.3 1.7 124 3 1906 2018 2017 2018 top-tenth 48 71.0 69.2 1.8 123 3 1915 2023 2018 2019 top-tenth 60 70.6 69.1 1.5 121 4 1977,1979 2020 2018 2019 top-tenth 2022