1991-2020 Degrees Fahrenheit 1 79.1 81.5 -2.4 6 70 1950 2000 1950 1957 bottom-tenth 1985 2 78.6 80.6 -2.0 12 64 1961 2011 1956 1957 bottom-third 1983 3 76.6 78.4 -1.8 12 64 1961 2022 1958 1957 bottom-third 1964,1967,1994 4 73.9 75.4 -1.5 16 60 1961 2022 1956 1957 bottom-third 1975,1979,1989 5 70.3 72.4 -2.1 10 66 1983 2015 1950 1957 bottom-third 6 65.8 69.4 -3.6 1 75 1958,1983 2012 1958 1957 lowest 1983 7 62.7 66.7 -4.0 2 74 1978 2012 1958 1957 bottom-tenth 8 61.3 65.0 -3.7 2 73 1978 2012 1958 1957 bottom-tenth 9 60.9 64.3 -3.4 3 72 1978 2017 1958 1957 bottom-tenth 1964,1969 10 61.1 64.7 -3.6 3 72 1977 2017 1958 1957 bottom-tenth 11 62.3 65.9 -3.6 2 73 1977 2017 1958 1957 bottom-tenth 12 63.8 67.2 -3.4 2 73 1977 2017 1958 1957 bottom-tenth 18 65.7 67.9 -2.2 8 67 1984 2017 1958 1957 bottom-third 1960,1968 24 65.6 67.1 -1.5 20 54 1978 2017 1958 1957 bottom-third 1980,1983,1993 36 65.7 67.1 -1.4 24 49 1970,1978,1979 2018 1958 1957 bottom-third 1982 48 65.9 67.0 -1.1 27 45 1971 2019,2020 1958 1957 normal 1995 60 66.1 67.0 -0.9 31 40 1970 2020 1958 1957 normal 1994,1998