1991-2020 Degrees Fahrenheit 1 51.9 57.9 -6.0 5 72 1958 1974 1969 2000 bottom-tenth 2 50.6 53.9 -3.3 13 64 1958 2017 1989 2000 bottom-third 3 47.9 51.3 -3.4 11 65 1978 2000,2017 1985 2000 bottom-third 4 46.0 50.2 -4.2 5 70 1978 2000 1984 2000 bottom-tenth 5 46.6 51.2 -4.6 1 74 2001 2000 2001 2000 lowest 6 50.1 53.8 -3.7 2 73 1977 2017 1977 2000 bottom-tenth 7 54.2 57.1 -2.9 4 71 1977,2010 2017 1977 2000 bottom-tenth 1973 8 58.4 60.4 -2.0 9 66 1977 2000,2017 1985 2000 bottom-third 2014 9 61.5 63.1 -1.6 12 63 1977 2017 1993 2000 bottom-third 1988,1993 10 63.3 64.9 -1.6 11 64 1977 2017 1993 2000 bottom-third 1975,1993 11 64.8 65.7 -0.9 20 55 1977 1999 1998 2000 bottom-third 12 65.1 65.7 -0.6 23 52 1977 2012 1998 2000 bottom-third 1959,1997 18 62.5 61.7 0.8 57 16 1959,1960 2023 1998 2000 top-third 24 66.4 65.7 0.7 57 16 1978 2000 1999 2000 top-third 1982,2007 36 66.9 65.7 1.2 64 7 1960 1955,1957 2000 1957 top-tenth 48 66.2 65.6 0.6 52 17 1996 1955 2000 2000 top-third 2000,2012,2015 60 66.0 65.6 0.4 45 22 1996 1957 2000 1968 top-third