1991-2020 Degrees Fahrenheit 1 48.5 47.0 1.5 65 18 1976 2015 1981 1979 top-third 2 52.1 52.4 -0.3 51 32 1976 1975 1981 1975 normal 1954 3 57.1 58.1 -1.0 42 41 1976 2015 1981 1979 normal 4 60.7 62.7 -2.0 27 56 1940 2015 1981 1980 bottom-third 1957 5 63.8 65.8 -2.0 23 60 1940 2016 1981 1980 bottom-third 1957,1960,1984,1987 6 64.6 67.0 -2.4 14 68 1976 2016,2020 1981 1980 bottom-third 1997 7 64.6 66.6 -2.0 18 64 1967 2015 1981 1980 bottom-third 1943,1947,1948,1951,1960,1965 8 62.8 65.0 -2.2 17 65 1967 2010,2015 1981 1980 bottom-third 9 60.4 62.6 -2.2 18 63 1967 2010 1981 1980 bottom-third 1944 10 57.7 59.9 -2.2 19 62 1967 2016 1979 1981 bottom-third 1948 11 54.7 57.4 -2.7 6 75 1967 2020 1978 1981 bottom-tenth 1943,1962,1984,1992 12 53.0 55.9 -2.9 10 71 1978,1996 2016 1981 1980 bottom-third 1948 18 56.7 59.5 -2.8 3 76 1963 2016 1978 1981 bottom-tenth 1943,1967,1977 24 52.9 55.8 -2.9 2 76 1963 2017 1978 1981 bottom-tenth 1967,1978 36 53.4 55.8 -2.4 9 66 1963 2021,2022 1979 1981 bottom-third 1944,1962 48 53.5 55.7 -2.2 11 61 1964,1965 2022 1981 1980 bottom-third 1944,1972,1980,1984 60 53.3 55.7 -2.4 4 65 1965,1967 2020 1981 1981 bottom-tenth 1964,1969,1970,1981