1991-2020 Degrees Fahrenheit 1 56.3 61.4 -5.1 7 69 1952 2016 1964 1965 bottom-tenth 2 62.6 67.1 -4.5 4 72 1976 2019 1952 1965 bottom-tenth 1988 3 67.0 71.2 -4.2 3 73 1976 2007 1966 1965 bottom-tenth 4 70.7 73.5 -2.8 4 72 1976 2007 1966 1965 bottom-tenth 5 71.4 74.2 -2.8 5 71 1976 2007 1966 1965 bottom-tenth 6 70.3 73.3 -3.0 5 71 1976 2007 1966 1965 bottom-tenth 7 68.5 71.5 -3.0 6 70 1976 2010,2019 1961 1965 bottom-tenth 8 66.2 68.9 -2.7 3 73 1976 2007 1961 1965 bottom-tenth 1960,1992 9 63.3 66.0 -2.7 5 71 1958 2016 1960 1965 bottom-tenth 1967 10 60.2 63.4 -3.2 4 72 1979 2012,2017,2019 1958 1965 bottom-tenth 11 58.7 61.5 -2.8 7 67 1978 2016 1963 1965 bottom-tenth 1960 12 58.1 60.6 -2.5 14 60 1978 2016 1964 1965 bottom-third 1977 18 62.8 64.8 -2.0 15 59 1977 2017 1964 1965 bottom-third 1960,1976,1980 24 58.5 60.6 -2.1 20 52 1979 2017 1965 1958 bottom-third 36 58.3 60.6 -2.3 14 56 1979 2018 1965 1959 bottom-third 1981 48 58.1 60.6 -2.5 7 61 1979 2019 1964 1965 bottom-tenth 1971,1978 60 58.3 60.5 -2.2 13 53 1964 2020 1965 1961 bottom-third 1961,1969