1991-2020 Degrees Fahrenheit 1 86.8 83.5 3.3 61 6 1974 1977 1979 1977 top-tenth 2 87.5 86.7 0.8 50 17 1971 2019 1979 1977 top-third 3 89.4 87.7 1.7 60 7 1976 1951 1979 1977 top-tenth 2015 4 89.7 87.6 2.1 63 4 1971 1951 1979 1953 top-tenth 1953 5 88.0 86.5 1.5 57 10 1976 1998 1979 1956 top-third 1996 6 85.7 84.6 1.1 55 11 1976 2011 1979 1956 top-third 2001 7 83.0 82.2 0.8 53 13 1987 2011 1979 1963 top-third 8 80.0 79.5 0.5 51 14 1987 2000 1979 1956 top-third 1986,1999 9 77.5 76.8 0.7 53 12 1987 2000 1979 1956 top-third 1952,1956,1986,1999 10 75.5 74.7 0.8 53 12 1968 2000 1979 1955 top-third 1952 11 74.1 73.7 0.4 49 16 1987 2000 1979 1955 top-third 1954,2016,2020 12 74.5 73.8 0.7 54 11 1968,1987 2000 1979 1955 top-third 1952,1998,2016 18 77.3 77.4 -0.1 42 22 1977 2000 1979 1956 normal 1996 24 73.0 73.8 -0.8 24 39 1971,1988 2000 1979 1972 normal 1972,1991,1992 36 73.0 73.8 -0.8 22 39 1970 2000 1979 1956 normal 1990 48 72.6 73.7 -1.1 12 47 1971 1955,2001,2019 1979 1975 bottom-third 1975,1988 60 72.5 73.7 -1.2 11 46 1979 1956,2002,2020 1979 1976 bottom-third 1981