1991-2020 Degrees Fahrenheit 1 77.6 80.0 -2.4 21 49 1977 1997 1959 1960 bottom-third 2 75.2 76.1 -0.9 32 37 1975 2000 1957 1960 normal 1972 3 71.4 72.8 -1.4 24 45 1975 2004 1957 1960 normal 4 68.9 69.7 -0.8 31 38 1975 2014 1957 1960 normal 1957,1994,2002 5 66.7 67.1 -0.4 42 25 1975 2014 1960 1959 normal 1972 6 64.5 65.3 -0.8 35 28 1975 2014,2015 1960 1959 normal 1968,1994 7 64.2 65.1 -0.9 34 29 1975 1996 1960 1959 normal 1993 8 65.6 66.6 -1.0 31 31 1973 1996,2015 1960 1959 normal 1990 9 68.1 69.0 -0.9 33 29 1973 1996 1960 1959 normal 10 70.7 71.5 -0.8 34 28 1973 1996 1960 1959 normal 11 72.9 73.5 -0.6 34 28 1973 1996 1960 1959 normal 12 74.5 74.8 -0.3 39 23 1973 1996 1960 1959 normal 18 70.9 71.7 -0.8 30 28 1976 2015,2018 1958 1960 normal 2020 24 74.3 74.9 -0.6 35 22 1973,1974 2018 1959 1960 normal 1959,1990,1993,2002 36 74.5 74.9 -0.4 34 18 1975 2017,2018 1960 1961 normal 2006 48 74.3 74.9 -0.6 28 19 1975,1976 2018 1960 1961 normal 60 74.1 74.8 -0.7 25 17 1977 2018 1960 1961 normal 1963,1993