1991-2020 Degrees Fahrenheit 1 4.1 17.3 -13.2 3 73 1992 2003 1984 1987 bottom-tenth 2 9.1 17.8 -8.7 6 68 1992 1981 1984 1987 bottom-tenth 3 15.0 22.0 -7.0 5 69 1992 2018 1984 1987 bottom-tenth 4 22.5 27.5 -5.0 6 68 1992 2018 1984 1987 bottom-tenth 5 28.4 33.2 -4.8 4 70 1992 2018 1984 1987 bottom-tenth 1993 6 34.0 38.2 -4.2 4 70 1992 2018 1979 1987 bottom-tenth 1979 7 38.2 42.1 -3.9 4 70 1992 2018 1973 1987 bottom-tenth 8 41.0 44.5 -3.5 5 69 1992 2018 1984 1987 bottom-tenth 1975,1977 9 42.0 45.3 -3.3 6 68 1992 2018 1984 1987 bottom-tenth 1968 10 42.0 45.0 -3.0 7 67 1992 2018 1984 1987 bottom-tenth 1979 11 41.0 44.1 -3.1 6 68 1992 2018 1984 1987 bottom-tenth 1993 12 39.5 42.5 -3.0 9 65 1965 2018 1984 1987 bottom-third 18 38.5 41.1 -2.6 8 64 1993 2018 1985 1987 bottom-third 1953,1965,1966,1973,1975,1989 24 40.6 42.5 -1.9 22 50 1993 2018 1985 1987 bottom-third 36 41.0 42.4 -1.4 36 34 1976,1994 2018 1986 1987 normal 1955,1979 48 40.7 42.2 -1.5 26 42 1976 2019 1987 1985 normal 1955,1962,1985 60 40.4 42.1 -1.7 12 54 1976 2020,2021,2022 1980 1987 bottom-third 1965,1973,1992,1995