1991-2020 Degrees Fahrenheit 1 33.4 38.2 -4.8 13 64 1978 1976 1980 1984 bottom-third 2 30.0 36.6 -6.6 8 69 1978 2017 1979 1984 bottom-tenth 3 35.5 37.4 -1.9 31 46 1977 2017 1984 1983 normal 1986,2021 4 37.6 39.6 -2.0 27 49 1977 2017 1984 1983 normal 1959 5 42.8 43.1 -0.3 44 32 1977 2017 1984 1983 normal 2013 6 46.5 47.3 -0.8 38 37 1977 2017 1984 1983 normal 7 50.5 51.2 -0.7 39 36 1977 2017 1984 1983 normal 1956,2007 8 53.3 54.3 -1.0 28 47 1977 2017 1982 1984 normal 9 55.6 56.3 -0.7 36 39 1977 2017 1984 1976 normal 1990 10 56.1 57.1 -1.0 32 43 1977 2017 1984 1983 normal 2007 11 55.9 57.1 -1.2 29 46 1977 2017 1984 1983 normal 12 54.6 56.2 -1.6 18 57 1977 2017 1982 1984 bottom-third 1962 18 51.7 53.2 -1.5 19 55 1978 2017 1982 1984 bottom-third 2010 24 54.7 56.1 -1.4 15 59 1978 2017 1982 1984 bottom-third 36 55.0 56.1 -1.1 20 53 1979 2018 1984 1976 bottom-third 1998 48 54.8 56.1 -1.3 17 55 1980 2020 1984 1977 bottom-third 1961,1967 60 54.7 56.0 -1.3 14 57 1981 2020 1984 1984 bottom-third 1962,1969,1984