1991-2020 Degrees Fahrenheit 1 72.3 74.6 -2.3 13 63 1972 2010 1980 1981 bottom-third 2 70.9 70.7 0.2 49 27 1992 2018 1981 1977 normal 2009 3 65.6 66.7 -1.1 27 49 1997 2010 1980 1981 normal 4 61.3 62.3 -1.0 33 43 1960 2012 1981 1981 normal 1981 5 57.2 58.2 -1.0 35 41 1958 2012 1980 1981 normal 1984,1987 6 52.9 54.9 -2.0 18 58 1958 2012 1980 1981 bottom-third 1965,1968 7 50.4 53.1 -2.7 10 65 1978 2012 1979 1981 bottom-third 1964 8 50.2 52.6 -2.4 13 62 1978 2012 1979 1981 bottom-third 1951 9 50.8 53.4 -2.6 9 66 1958,1978 2012 1979 1981 bottom-third 1956,1966 10 52.5 55.1 -2.6 7 68 1958 2017 1978 1981 bottom-tenth 11 54.5 57.1 -2.6 6 69 1958,1977 2017 1978 1981 bottom-tenth 12 56.5 58.8 -2.3 6 69 1977 2017 1977 1981 bottom-tenth 18 55.4 57.6 -2.2 9 66 1961,1963,1979 2012 1980 1981 bottom-third 1959,1966,1968,1997 24 57.2 58.8 -1.6 17 57 1978 2017 1980 1981 bottom-third 1962,1977 36 57.1 58.8 -1.7 14 59 1970,1979 2018 1980 1981 bottom-third 1962 48 57.1 58.8 -1.7 14 58 1980 2020 1980 1981 bottom-third 60 57.0 58.7 -1.7 10 61 1967,1970 2020 1981 1980 bottom-third 1962,1963,1972,1980