1991-2020 Degrees Fahrenheit 1 68.6 66.3 2.3 117 13 1983 2002 1933 1930 top-tenth 2 63.6 62.4 1.2 117 13 1973 2017 1933 1925 top-tenth 1907,2023 3 60.5 58.7 1.8 123 7 1973 2017 1933 1925 top-tenth 4 56.9 55.6 1.3 119 9 1964 2017 1933 1916 top-tenth 1986,2014 5 55.6 53.7 1.9 122 5 1913 2017 1933 1907 top-tenth 6 55.7 53.7 2.0 122 5 1913 2017 1933 1907 top-tenth 7 57.6 55.5 2.1 124 3 1913 2017 1933 1934 top-tenth 8 60.4 58.2 2.2 124 3 1913 2017 1933 1934 top-tenth 9 62.9 60.8 2.1 124 3 1913 2017 1933 1934 top-tenth 10 65.1 63.2 1.9 124 3 1913 2017 1933 1934 top-tenth 11 66.5 65.0 1.5 122 5 1913 2017 1933 1934 top-tenth 12 66.9 65.9 1.0 120 7 1913 2017 1933 1934 top-tenth 2019,2023 18 61.8 61.8 0.0 105 19 1913 2018 1933 1928 top-third 1928,1957,1997 24 65.4 65.9 -0.5 92 32 1913 2018 1933 1928 top-third 1957,2001 36 65.4 65.8 -0.4 91 30 1915 2019 1933 1934 top-third 2010 48 65.1 65.8 -0.7 83 35 1915 2020 1933 1928 top-third 1928,1954,1955,1984,1995 60 64.9 65.7 -0.8 72 43 1916,1977 2021 1933 1929 normal 1911,1953,1958,1984,1985,1986