1901-2000 Degrees Fahrenheit 1 37.2 34.1 3.1 102 28 1933 1995,2015 1897 1898 top-third 1961 2 29.6 32.1 -2.5 23 107 1949 2015 1895 1897 bottom-third 3 29.3 31.7 -2.4 18 111 1949 2015 1898 1897 bottom-third 4 32.0 33.6 -1.6 23 106 1949 2015 1898 1897 bottom-third 1906,1944,1972 5 35.3 37.0 -1.7 20 109 1949 2015 1898 1897 bottom-third 6 39.6 41.1 -1.5 20 109 1949 2015 1898 1897 bottom-third 1993 7 44.3 45.2 -0.9 27 102 1949 2015 1898 1897 bottom-third 1969 8 47.5 48.6 -1.1 21 108 1949 2015 1898 1897 bottom-third 1919,1972,1993 9 49.2 50.3 -1.1 21 108 1949 2015 1898 1897 bottom-third 1948,1972 10 50.3 50.8 -0.5 31 98 1917 2015 1898 1897 bottom-third 1915,1947,1948,1957,1962,1969,1983 11 50.1 50.4 -0.3 44 85 1949 2015 1897 1896 normal 1904,1907,1915,1936,1944,1999 12 48.5 49.5 -1.0 20 109 1949 2015 1898 1897 bottom-third 1955 18 46.1 46.7 -0.6 26 102 1949 2016 1898 1897 bottom-third 1923,1938,1984,1985,1994 24 48.8 49.5 -0.7 20 108 1913 2016 1898 1897 bottom-third 1899,1909,1925,1947,1984 36 48.9 49.5 -0.6 18 109 1914 2016,2017 1898 1898 bottom-third 1899,1909,1912,1925,1957,1974 48 -99 49.5 -99 -99 -99 1915,1949 2018 normal 60 -99 49.4 -99 -99 -99 1917,1949 2018 normal