1991-2020 Degrees Fahrenheit 1 78.9 73.7 5.2 113 4 1915 1937 1936 1937 top-tenth 2 78.3 75.0 3.3 107 8 1915 1934 1933 1937 top-tenth 3 76.0 73.5 2.5 106 8 1915 1934 1937 1936 top-tenth 1952 4 71.7 70.0 1.7 102 11 1915 1934 1935 1937 top-tenth 2018 5 67.3 65.9 1.4 97 15 1915 1934 1935 1937 top-third 1977 6 63.6 61.8 1.8 107 5 1915 2012 1937 1936 top-tenth 2006 7 59.3 57.6 1.7 105 6 1915 2012 1937 1934 top-tenth 2016 8 55.9 54.2 1.7 104 6 1915 2012 1937 1934 top-tenth 2016 9 52.8 51.6 1.2 99 10 1915 1934 1937 1934 top-tenth 2002 10 51.3 50.4 0.9 94 15 1915 1934 1937 1934 top-third 1981 11 51.5 50.5 1.0 95 14 1915 1934 1937 1935 top-third 2015 12 52.9 51.8 1.1 94 13 1915 1934 1937 1934 top-third 2020 18 55.9 55.1 0.8 94 13 1916,1924 1934 1937 1935 top-third 1954 24 51.7 51.7 0.0 76 29 1916 1935 1937 1936 top-third 1956,1982,2020 36 51.5 51.7 -0.2 72 31 1917 2017 1937 1936 top-third 1964,1977,1982,1987,1988 48 51.8 51.7 0.1 74 27 1918 2018 1933 1937 top-third 1955,1957,2021 60 52.5 51.7 0.8 92 7 1927,1928,1930,1931 2003,2006 1937 1938 top-tenth 2004,2019