1991-2020 Degrees Fahrenheit 1 57.1 57.3 -0.2 48 37 1976 1965 1974 1973 normal 2 63.0 62.7 0.3 60 25 1976 2016 1974 1973 top-third 1942 3 66.8 68.1 -1.3 29 56 1976 2016 1974 1973 normal 1958,2001 4 70.5 72.3 -1.8 24 61 1976 2016 1974 1973 bottom-third 1966,1989,1997 5 72.8 74.7 -1.9 17 68 1976 2011,2016 1974 1973 bottom-third 1946,1989 6 73.8 75.9 -2.1 14 70 1976 2011 1974 1973 bottom-third 1946,1972 7 73.7 75.7 -2.0 14 70 1976 1998 1974 1973 bottom-third 1957,1983,1989 8 72.6 74.6 -2.0 15 69 1976 2011 1974 1972 bottom-third 9 70.8 72.9 -2.1 13 71 1976 2011 1968 1974 bottom-third 1958 10 68.6 70.9 -2.3 11 73 1940 2011,2016 1968 1974 bottom-third 1989,1993 11 67.0 68.9 -1.9 19 65 1940 2016 1973 1974 bottom-third 1984 12 65.5 67.3 -1.8 18 66 1940 2016 1973 1974 bottom-third 1946,1951,1981,1982 18 67.9 70.2 -2.3 6 77 1968 2016 1968 1974 bottom-tenth 1958,1959,1961,1976,1983,1993 24 65.6 67.3 -1.7 18 65 1979 2017 1974 1973 bottom-third 1946,1977,1978,1993 36 65.4 67.3 -1.9 14 68 1961 2017,2018 1970 1974 bottom-third 1976,1978 48 65.7 67.2 -1.5 22 59 1961 2018 1971 1974 bottom-third 1949,1959 60 65.9 67.2 -1.3 32 48 1962 2019,2020 1974 1967 normal 1945,1952,1959,1965