1991-2020 Degrees Fahrenheit 1 73.0 75.1 -2.1 57 73 1917 1996 2015 2014 normal 2 69.2 70.7 -1.5 70 60 1983 2006,2018 2015 2014 normal 1956,1984 3 66.6 66.6 0.0 107 23 1973 2018 2015 2013 top-third 1896 4 63.1 62.7 0.4 113 17 1973 2018 2015 2014 top-third 1904,1927,2012 5 59.5 59.4 0.1 100 28 1973 2006,2017,2018 2015 2014 top-third 1995 6 57.3 57.2 0.1 103 24 1913 2006,2017 2015 2014 top-third 2019,2021 7 56.9 56.7 0.2 103 24 1913 2018 2015 2014 top-third 1936,2011 8 58.3 57.9 0.4 108 19 1977 2018 2015 2011 top-third 1902,1925,2011 9 60.7 60.0 0.7 114 13 1977 2018 2015 2006 top-tenth 10 63.1 62.2 0.9 117 10 1977 2018 2015 2006 top-tenth 11 65.0 64.2 0.8 116 11 1977 2017,2018 2015 2006 top-tenth 1935 12 66.6 65.8 0.8 116 11 1977 2017,2018 2015 2012 top-tenth 1935,2012 18 63.4 62.9 0.5 111 13 1913 2018 2015 2012 top-third 24 66.2 65.8 0.4 111 13 1913 2018 2015 2013 top-third 2006,2013 36 66.1 65.8 0.3 109 12 1915 2018 2015 2014 top-tenth 1997,2004,2014 48 66.0 65.7 0.3 107 11 1915 2020 2015 2015 top-tenth 2015 60 66.1 65.7 0.4 107 8 1977 2021 2015 2015 top-tenth 2006,2015