1991-2020 Degrees Fahrenheit 1 49.7 52.5 -2.8 32 53 1978 2017 1969 1965 normal 2 46.0 50.6 -4.6 15 70 1978 2017 1968 1969 bottom-third 2015 3 46.9 50.5 -3.6 16 69 1978 2017 1968 1969 bottom-third 2014 4 48.9 52.1 -3.2 16 69 1978 2017 1964 1969 bottom-third 5 52.8 55.3 -2.5 19 66 1977 2017 1968 1969 bottom-third 1959 6 57.0 59.3 -2.3 20 65 1977 2017 1969 1967 bottom-third 1941,1947,1959,1964 7 61.0 62.9 -1.9 26 59 1977 2017 1969 1966 bottom-third 1962 8 64.2 65.6 -1.4 34 51 1977 2017 1969 1966 normal 1942,2001 9 66.1 67.4 -1.3 36 48 1977 2017 1969 1966 normal 1966,1974 10 66.7 68.1 -1.4 29 55 1977 2017 1969 1966 normal 1974,1988,1990,1994 11 66.6 68.0 -1.4 33 51 1977 2017 1969 1966 normal 1987 12 65.3 67.3 -2.0 17 67 1977 2017 1969 1968 bottom-third 1993 18 62.5 64.6 -2.1 13 71 1978,1984 2017 1969 1968 bottom-third 1962 24 65.2 67.3 -2.1 11 72 1978 2017 1969 1969 bottom-third 1948,1969,1980 36 65.3 67.2 -1.9 10 72 1979 2018 1963 1969 bottom-third 1980 48 65.3 67.2 -1.9 8 73 1980 2019 1963 1969 bottom-tenth 1977,1984 60 65.4 67.2 -1.8 10 70 1962,1963 2020 1964 1969 bottom-third 1961,1985