1991-2020 Degrees Fahrenheit 1 46.5 47.7 -1.2 34 41 1977 1950 1994 1999 normal 2 47.7 48.9 -1.2 32 43 1977 1950 1996 1999 normal 3 51.0 51.2 -0.2 41 33 1977 1974 1998 1999 normal 1967,1979 4 54.7 54.9 -0.2 42 32 1977 1974,2017 1998 1999 normal 1960,1962,1989 5 58.6 59.1 -0.5 34 40 1977 1974 1998 1999 normal 6 62.9 62.9 0.0 47 27 1977 2017 1998 1999 normal 1986 7 65.6 65.7 -0.1 49 25 1977 2017 1998 1999 normal 1983 8 67.2 67.4 -0.2 46 28 1977 2017 1998 1999 normal 1983,2009 9 67.7 68.0 -0.3 41 33 1977 2017 1998 1999 normal 1992,2009,2018 10 67.7 67.7 0.0 50 24 1977 2017 1998 1999 top-third 1986 11 66.5 66.7 -0.2 45 29 1977 2017 1998 1999 normal 1953,1978,1995,2003 12 65.4 65.5 -0.1 52 22 1977 2017 1998 1999 top-third 1958,1986,2002,2007,2008 18 65.3 64.5 0.8 63 9 1969,1977 2017 1999 1992 top-third 1975,1987,1992 24 66.1 65.4 0.7 64 8 1970 2017,2020 1999 1992 top-third 36 65.5 65.3 0.2 55 15 1970 2019,2021 1999 1993 top-third 1955,1956,1987,1993 48 65.2 65.3 -0.1 44 24 1970 2020 1999 1993 normal 1988,1989,1993,2005,2007,2012,2016 60 65.1 65.3 -0.2 42 24 1970 2020,2021 1999 1999 normal 1987,1989,1992,1993,1995,1999,2010,2014,2015