1991-2020 Degrees Fahrenheit 1 27.6 28.3 -0.7 74 51 1978 2017 2011 2012 normal 2 27.8 26.8 1.0 86 35 1912 2017 2011 2012 top-third 1989 3 30.7 28.1 2.6 107 12 1904 1932 2011 2012 top-tenth 1954 4 33.2 31.3 1.9 105 13 1904 1932 2011 2012 top-third 1976 5 36.7 35.7 1.0 96 21 1904 1932 2011 2012 top-third 1950 6 41.2 40.6 0.6 93 24 1977 1932 2011 2012 top-third 1964,2018 7 45.4 45.0 0.4 91 26 1977 1932 2011 2012 top-third 1898,1919 8 49.7 48.6 1.1 103 14 1977 1932 2011 2012 top-third 1909,1992 9 52.1 51.0 1.1 103 14 1904 1932 2011 2012 top-third 10 53.4 51.9 1.5 106 11 1918 1932 2011 2012 top-tenth 2006,2022 11 53.1 51.7 1.4 105 11 1918 1932 2011 2012 top-tenth 2022 12 53.1 50.5 2.6 114 2 1918 2017 2012 2013 top-tenth 18 49.8 47.2 2.6 107 2 1918 2017 2012 2013 top-tenth 24 52.6 50.5 2.1 106 2 1918 2017 2012 2013 top-tenth 36 52.1 50.5 1.6 99 2 1918 2018 2012 2013 top-tenth 48 51.4 50.5 0.9 90 5 1980 2019 2012 2002 top-tenth 60 50.8 50.4 0.4 80 10 1981 2020 2012 2003 top-third 1992,2016