1991-2020 Degrees Fahrenheit 1 43.5 39.6 3.9 52 8 1976 2001 1989 1975 top-third 2 46.9 45.4 1.5 45 15 1976 1975,2016 1989 1984 top-third 2005 3 52.3 51.3 1.0 44 16 1976 2016 1989 1975 top-third 1999 4 56.5 56.2 0.3 43 17 1976 2016 1989 1984 top-third 1968 5 59.3 59.4 -0.1 36 24 1992 2016 1989 1984 normal 2013 6 60.7 60.9 -0.2 34 26 1992 2016 1989 1988 normal 1966,1968,1988,2006 7 59.9 60.6 -0.7 24 36 1992 2016 1989 1988 normal 2000,2008,2019 8 58.4 59.0 -0.6 26 34 1992 2010 1989 1988 normal 2019 9 56.1 56.4 -0.3 34 26 1992 2012 1989 1988 normal 1971,1994 10 53.3 53.4 -0.1 36 24 1967,1978 2012 1989 1987 normal 11 51.4 50.7 0.7 46 14 1978,2014 2012 1989 1987 top-third 2000,2005 12 48.6 49.0 -0.4 35 25 1978,2014 2012 1989 1987 normal 18 52.0 53.0 -1.0 23 36 1978 2012 1989 1988 normal 2009 24 47.8 49.0 -1.2 21 38 1979 2017 1989 1989 normal 1977,1989 36 48.0 48.9 -0.9 19 39 1980 2012 1986 1989 bottom-third 1976 48 48.5 48.9 -0.4 33 24 1981 2013 1989 1988 normal 1976,1988,1991 60 48.3 48.9 -0.6 28 28 1982 2002,2013,2020 1989 1988 normal 1988,1992