1991-2020 Degrees Fahrenheit 1 56.5 57.7 -1.2 36 57 1989 2021 1967 1965 normal 2 58.5 61.0 -2.5 20 73 1976 2021 1963 1967 bottom-third 3 63.8 65.3 -1.5 26 62 1976 2021 1966 1967 bottom-third 4 67.7 69.5 -1.8 20 68 1976 2021 1959 1967 bottom-third 5 71.1 72.9 -1.8 20 68 1976 2021 1967 1965 bottom-third 6 73.2 75.0 -1.8 12 75 1976 2016 1967 1966 bottom-third 1959,1961 7 74.3 76.3 -2.0 11 76 1976 2021 1967 1966 bottom-third 8 74.7 76.6 -1.9 12 75 1976 2021 1967 1966 bottom-third 1961,1966,1974 9 74.4 76.0 -1.6 15 71 1976 2016 1966 1967 bottom-third 10 72.9 75.0 -2.1 8 78 1976 2016 1952 1967 bottom-tenth 1931,1936,1975 11 71.0 73.6 -2.6 4 81 1976 2016 1968 1967 bottom-tenth 1989 12 69.5 72.1 -2.6 6 78 1979 2017 1966 1967 bottom-tenth 1936,1966 18 70.6 73.1 -2.5 5 77 1976 2017 1940 1967 bottom-tenth 24 70.3 72.1 -1.8 13 66 1979 2017 1967 1967 bottom-third 1959,1967 36 70.0 72.1 -2.1 4 71 1979,1980 2017,2018 1961 1967 bottom-tenth 1961,1977,1981 48 70.5 72.1 -1.6 15 56 1979 2018,2019 1963 1967 bottom-third 1960,1963,1985 60 70.4 72.1 -1.7 11 57 1979,1980 2020 1964 1967 bottom-third 1961,1964,1984