1991-2020 Degrees Fahrenheit 1 35.3 41.2 -5.9 6 70 1950 1987 1953 1965 bottom-tenth 2 33.1 35.5 -2.4 31 45 1950 2012 1965 1963 normal 3 25.9 30.1 -4.2 22 54 1950 2012 1965 1964 bottom-third 1959 4 19.9 26.6 -6.7 10 66 1950 2012 1965 1964 bottom-third 5 20.7 25.2 -4.5 20 55 1950 1992,2012 1965 1964 bottom-third 6 21.8 26.0 -4.2 21 54 1979 2012 1965 1964 bottom-third 1970 7 25.6 28.5 -2.9 27 48 1979 2012 1965 1964 normal 8 27.9 32.2 -4.3 13 62 1950 2012 1965 1964 bottom-third 9 32.1 36.2 -4.1 11 64 1952,1965 2012 1965 1964 bottom-third 10 35.7 39.5 -3.8 11 64 1952 2012 1965 1964 bottom-third 1982 11 38.0 41.5 -3.5 12 62 1952 2012 1965 1964 bottom-third 12 39.1 42.4 -3.3 11 63 1951,1952 2016 1965 1964 bottom-third 1982 18 31.8 36.9 -5.1 5 68 1951 2016 1952 1965 bottom-tenth 24 38.5 42.4 -3.9 4 68 1952 2000 1952 1965 bottom-tenth 36 40.2 42.4 -2.2 12 58 1952 2000 1957 1965 bottom-third 1954 48 40.5 42.4 -1.9 15 53 1953 1992 1960 1965 bottom-third 1955,1957,1958,1960,1974,1975 60 40.4 42.5 -2.1 13 53 1954 1992 1960 1965 bottom-third 1959