1901-2000 Degrees Fahrenheit 1 9.8 12.9 -3.1 35 94 1983 2015 1927 1931 bottom-third 2 16.9 20.4 -3.5 24 105 1985 2001 1927 1931 bottom-third 1945,1947 3 25.0 28.6 -3.6 17 112 1919 2015 1927 1931 bottom-third 4 32.8 35.7 -2.9 14 115 1985 2015 1927 1931 bottom-third 5 39.7 41.8 -2.1 16 113 1985 2015 1927 1931 bottom-third 6 44.7 46.3 -1.6 20 109 1985 2015 1927 1931 bottom-third 1942 7 48.0 48.8 -0.8 33 96 1985 1931,2021 1929 1931 bottom-third 8 48.9 49.5 -0.6 38 91 1917 2021 1929 1931 bottom-third 9 48.1 48.6 -0.5 38 91 1917 2015,2021 1929 1931 bottom-third 1915,1947,1958,1976 10 45.0 46.2 -1.2 22 107 1917,1950 2021 1927 1931 bottom-third 1935,1965 11 42.1 43.1 -1.0 30 99 1917 1987 1929 1931 bottom-third 12 39.6 40.1 -0.5 42 87 1917 1987 1929 1931 bottom-third 1898,1911,1956,1971 18 43.4 42.2 1.2 97 31 1917 2012 1930 1931 top-third 1900,1942,1990 24 42.3 40.1 2.2 112 16 1917 1999 1930 1931 top-third 2013 36 41.9 40.1 1.8 108 19 1917,1918 2017 1931 1932 top-third 48 40.8 40.0 0.8 85 41 1919 2001 1930 1931 top-third 1923,1976,1998 60 40.8 40.0 0.8 88 37 1907,1920 2002 1931 1932 top-third 1933,1977