1991-2020 Degrees Fahrenheit 1 65.1 64.3 0.8 63 30 1976 1973 1976 1973 top-third 2 69.2 69.1 0.1 64 24 1976 2016 1976 1973 top-third 1971,1983,1989,1996,1999 3 73.9 73.5 0.4 70 18 1976 2016 1976 1973 top-third 4 76.7 76.6 0.1 67 21 1976 2016 1976 1973 top-third 2003,2010 5 78.4 78.5 -0.1 66 21 1976 2016 1976 1973 top-third 1973,1985,1999,2010 6 79.2 79.4 -0.2 64 23 1976 1998,2016 1976 1965 top-third 1985,1990,2003,2013,2018 7 79.0 79.3 -0.3 59 28 1976 1998 1976 1965 top-third 1951,1999,2012 8 77.9 78.3 -0.4 50 36 1976 2011 1976 1965 normal 1934,1941,1953,2018 9 76.4 76.9 -0.5 52 34 1976 2011 1976 1965 normal 1954,1956,1994 10 74.5 75.2 -0.7 50 35 1976 2017 1976 1963 normal 1948,1994,1996,2001 11 71.9 73.5 -1.6 24 60 1940 2017 1976 1974 bottom-third 12 70.3 72.1 -1.8 19 65 1979 2017 1976 1975 bottom-third 18 71.7 74.5 -2.8 1 81 1977 2017 1977 1976 lowest 24 69.7 72.1 -2.4 4 75 1979 2017 1977 1976 bottom-tenth 1978 36 70.0 72.1 -2.1 7 68 1979,1980 2017,2018 1970 1976 bottom-tenth 1984 48 70.3 72.1 -1.8 10 61 1979 2019 1976 1975 bottom-third 1962,1969,1971 60 70.2 72.1 -1.9 8 60 1980 2020 1970 1976 bottom-third 1984