1901-2000 Degrees Fahrenheit 1 50.6 47.8 2.8 96 34 1940 1950 1919 1917 top-third 2 50.3 48.4 1.9 92 37 1977 1950 1919 1917 top-third 3 53.8 50.9 2.9 111 18 1977 1932 1919 1909 top-third 4 59.3 54.6 4.7 125 4 1977 1932 1919 1920 top-tenth 5 62.7 58.8 3.9 125 4 1977 1932 1919 1920 top-tenth 6 65.4 62.4 3.0 124 5 1977 1932 1919 1920 top-tenth 1950 7 67.5 64.9 2.6 123 6 1977 1932 1919 1920 top-tenth 1950 8 68.9 66.6 2.3 122 7 1977 1932 1919 1920 top-tenth 9 69.1 67.3 1.8 118 11 1977 1999 1919 1916 top-tenth 1974 10 68.7 67.0 1.7 119 10 1977 1999,2017 1919 1916 top-tenth 1950 11 67.8 66.1 1.7 121 8 1977 2017 1919 1909 top-tenth 1909,1922,1949 12 66.2 64.8 1.4 112 17 1902 2017 1919 1920 top-third 1934,1987 18 64.9 64.0 0.9 103 25 1970,1977,1978 2017 1919 1920 top-third 2007 24 65.8 64.8 1.0 113 15 1970 2017 1919 1920 top-third 36 64.7 64.8 -0.1 50 77 1904 2018,2019 1919 1917 normal 1916,2012,2015,2016 48 64.8 64.8 0.0 51 75 1905 2020 1919 1917 normal 1909,1910,1914,1915,1917,2004 60 65.0 64.8 0.2 72 53 1906 2020 1919 1916 normal 1916,1931,1940,1946,1960,1975,1987,1994,2007,2010