1991-2020 Degrees Fahrenheit 1 51.4 51.9 -0.5 57 72 1927 1936 1927 1928 normal 2 45.8 47.3 -1.5 37 92 1975 1934 1927 1928 bottom-third 3 42.4 43.0 -0.6 54 75 2002 1910 1927 1928 normal 1908,1924,1974 4 35.0 38.9 -3.9 19 110 1899 1934,1987 1922 1928 bottom-third 1978 5 29.3 36.2 -6.9 7 122 1899 1934 1916 1928 bottom-tenth 1978,2019 6 29.0 34.5 -5.5 10 118 1969 1992 1922 1928 bottom-tenth 1916,1922,1965 7 30.1 34.4 -4.3 18 110 1979 1992 1922 1928 bottom-third 1975,2011 8 31.8 35.8 -4.0 13 114 1899 1987 1922 1928 bottom-tenth 1956,1962,2019 9 34.4 38.2 -3.8 15 112 1899 1934,1987,1992 1922 1928 bottom-third 1916,1956,1965 10 37.2 41.1 -3.9 9 118 1899 1992 1922 1928 bottom-tenth 1920 11 39.9 43.6 -3.7 8 119 1899 1934,1992 1922 1928 bottom-tenth 1907 12 41.4 44.9 -3.5 10 117 1899 1934 1917 1928 bottom-tenth 1951,1982 18 38.8 41.4 -2.6 18 108 1979 1988 1918 1928 bottom-third 24 42.3 44.9 -2.6 12 113 1917,1979 1988,2013 1918 1928 bottom-tenth 1904,1907,1950 36 42.4 44.9 -2.5 6 117 1952 2000 1918 1928 bottom-tenth 48 43.4 45.0 -1.6 30 91 1952 1934 1920 1928 bottom-third 1904,1905,1969,1981,1985 60 43.6 45.0 -1.4 40 79 1952 2016 1921 1928 normal 1904,1971,1998