1991-2020 Degrees Fahrenheit 1 72.6 71.9 0.7 96 32 1924 2012 1920 1919 top-third 2 71.7 69.7 2.0 118 10 1929 2012 1920 1919 top-tenth 1955 3 67.5 65.8 1.7 116 11 1917 2012 1920 1911 top-tenth 4 62.9 61.0 1.9 118 8 1917 1991 1920 1921 top-tenth 1977 5 58.0 56.0 2.0 118 6 1917,1924,1926 2012 1920 1921 top-tenth 6 53.4 51.3 2.1 117 7 1917 2012 1920 1921 top-tenth 7 50.2 47.8 2.4 117 5 1917 2012 1920 1921 top-tenth 8 48.0 45.8 2.2 117 5 1904 2012 1920 1921 top-tenth 9 47.2 45.2 2.0 116 6 1904 2012 1920 1921 top-tenth 1999,2002 10 48.3 45.9 2.4 120 2 1904 2012 1920 1921 top-tenth 11 50.0 47.5 2.5 120 2 1918 2012 1920 1921 top-tenth 12 51.4 49.4 2.0 118 4 1904 2012 1920 1921 top-tenth 18 49.7 50.0 -0.3 89 29 1918 2012 1920 1921 top-third 1989,1995 24 48.3 49.4 -1.1 66 50 1918 2017 1920 1921 normal 1985 36 48.7 49.4 -0.7 76 36 1918 2012 1920 1921 top-third 1954 48 47.6 49.4 -1.8 21 87 1918 2013 1920 1903 bottom-third 1939,1947,1948,1953,1961 60 47.1 49.4 -2.3 10 95 1920,1927 2002 1920 1904 bottom-tenth 1904