1925-2000 Degrees Fahrenheit 1 45.2 49.2 -4.0 2 97 1949 2004 1949 1954 bottom-tenth 2 40.5 43.5 -3.0 5 94 1949 2004 1952 1954 bottom-tenth 3 32.9 36.8 -3.9 3 96 1949 2016 1949 1954 bottom-tenth 1972 4 27.3 30.3 -3.0 8 91 1972 2019 1927 1954 bottom-tenth 5 21.4 25.2 -3.8 4 95 1972 2019 1955 1954 bottom-tenth 6 19.2 21.3 -2.1 17 82 1971 2016 1954 1953 bottom-third 7 15.4 18.8 -3.4 4 94 1971 2016 1955 1954 bottom-tenth 1966,1975 8 15.7 17.9 -2.2 14 84 1972 2016 1949 1954 bottom-third 9 17.3 18.8 -1.5 19 79 1971 2016 1954 1953 bottom-third 1959,1962 10 19.6 21.0 -1.4 17 81 1971 2019 1954 1954 bottom-third 1943,1954,1959 11 22.4 23.6 -1.2 19 79 1971 2019 1954 1953 bottom-third 1932,1943 12 24.7 26.0 -1.3 15 83 1971 2019 1949 1954 bottom-third 1962 18 22.8 24.4 -1.6 14 84 1972 2016 1952 1954 bottom-third 1952 24 24.8 26.0 -1.2 15 82 1972 2019 1950 1954 bottom-third 1967,1974 36 25.5 26.0 -0.5 26 70 1973 2016 1952 1954 bottom-third 1936,1961 48 25.4 25.9 -0.5 25 70 1974 2019 1954 1954 bottom-third 1954,1964,1969 60 25.3 25.9 -0.6 21 73 1975 2019 1953 1954 bottom-third 1935,1937,1960,1965,1969