1991-2020 Degrees Fahrenheit 1 35.8 34.8 1.0 62 14 1964 2017 1985 1974 top-third 2 32.3 29.4 2.9 70 6 1984 2017 1985 1986 top-tenth 3 29.5 25.2 4.3 72 4 1984 1995,1999,2015 1985 1986 top-tenth 4 26.3 23.2 3.1 66 8 1992 1999 1985 1981 top-third 5 26.8 24.6 2.2 65 9 1992 2018 1985 1981 top-third 2003,2006,2022 6 29.5 27.7 1.8 63 11 1992 2018 1985 1978 top-third 7 32.6 31.7 0.9 56 18 1992 2018 1985 1981 top-third 8 36.3 35.6 0.7 54 20 1992 2018 1985 1981 top-third 9 39.4 38.9 0.5 54 20 1992 2018 1985 1981 top-third 1967,2005 10 41.4 41.0 0.4 55 19 1992 2018 1985 1981 top-third 1996,2005 11 42.2 41.9 0.3 55 19 1992 2018 1985 1981 top-third 1967 12 42.3 42.0 0.3 56 18 1984 2018 1985 1978 top-third 2001,2019,2020 18 37.0 37.2 -0.2 48 24 1993 2018 1985 1982 top-third 2020 24 41.6 42.0 -0.4 47 25 1993 2018 1985 1982 normal 36 39.9 41.9 -2.0 12 58 1975 2018 1985 1983 bottom-third 1965,1970,1979,1989 48 40.2 41.7 -1.5 19 49 1976 2019 1985 1984 bottom-third 1967,1969 60 40.5 41.6 -1.1 31 35 1977 2020,2021,2022 1985 1983 normal 1954,1955,1963