1991-2020 Degrees Fahrenheit 1 56.0 56.4 -0.4 56 37 1958 2017 1984 1982 normal 2 49.8 52.5 -2.7 24 69 1958 2017 1981 1984 bottom-third 1931,1933,1979,1981,2001 3 45.5 49.7 -4.2 9 82 1958 2017 1979 1984 bottom-tenth 1973 4 46.0 48.5 -2.5 23 68 1964 2017 1984 1983 bottom-third 5 46.8 49.3 -2.5 18 73 1958 2017 1984 1983 bottom-third 1939,1942,1959 6 49.1 51.9 -2.8 11 80 1958 2017 1979 1984 bottom-third 1959,2010 7 52.2 55.1 -2.9 7 84 1977 2017 1979 1984 bottom-tenth 1979 8 55.6 58.4 -2.8 6 85 1977 2017 1979 1984 bottom-tenth 1979 9 58.4 61.1 -2.7 8 83 1977 2017 1977 1984 bottom-tenth 10 60.4 63.1 -2.7 8 83 1977 2017 1977 1984 bottom-tenth 11 61.6 64.0 -2.4 9 81 1977 1999 1977 1984 bottom-tenth 1942 12 61.7 64.1 -2.4 11 79 1977 1999,2017 1977 1984 bottom-third 18 57.8 60.0 -2.2 8 81 1977 2017 1977 1984 bottom-tenth 1961,1969 24 62.2 64.1 -1.9 15 73 1977 2000 1978 1984 bottom-third 1974 36 62.4 64.0 -1.6 13 73 1977 2018 1979 1984 bottom-third 1969,1973 48 62.6 64.0 -1.4 23 61 1961,1977 2019,2020 1979 1969 bottom-third 1946,1965,1969,1989 60 -99 64.0 -99 -99 -99 1962,1977 2020 normal