1991-2020 Degrees Fahrenheit 1 54.5 55.9 -1.4 20 47 1989 2021 1967 1965 bottom-third 2 58.0 59.7 -1.7 15 52 1976 2021 1963 1967 bottom-third 3 64.1 64.8 -0.7 23 44 1976 2021 1967 1966 normal 1970,2011 4 68.2 69.4 -1.2 13 54 1976 2021 1967 1966 bottom-third 5 72.3 73.5 -1.2 12 55 1976 2021 1967 1966 bottom-third 1969,1975 6 74.7 76.2 -1.5 8 59 1976 2021 1967 1966 bottom-third 1971,2008 7 76.3 77.8 -1.5 8 59 1976 2021 1967 1966 bottom-third 8 76.8 78.3 -1.5 10 57 1976 1998,2021 1967 1967 bottom-third 1967 9 76.3 78.0 -1.7 7 59 1976 2011 1968 1967 bottom-tenth 1970,1971 10 74.8 77.0 -2.2 4 62 1976 2011 1968 1967 bottom-tenth 11 72.9 75.5 -2.6 3 62 1976 2011 1968 1967 bottom-tenth 12 71.2 73.8 -2.6 2 63 1976 2011,2012 1968 1967 bottom-tenth 18 72.2 74.6 -2.4 2 63 1976 2012 1968 1967 bottom-tenth 24 72.2 73.8 -1.6 7 56 1976 2012 1966 1967 bottom-third 1966,1979 36 72.0 73.8 -1.8 2 59 1970 2000 1968 1967 bottom-tenth 1976,1977 48 72.2 73.8 -1.6 7 52 1971,1976 2001 1968 1967 bottom-third 60 72.4 73.7 -1.3 10 47 1970 1956,2002 1968 1956 bottom-third 1974