1991-2020 Degrees Fahrenheit 1 43.8 39.6 4.2 54 6 1976 2001 2008 2001 top-tenth 1999 2 45.9 45.4 0.5 37 23 1976 1975,2016 2008 2007 normal 2000 3 51.7 51.3 0.4 40 20 1976 2016 2008 2007 top-third 1982 4 56.0 56.2 -0.2 37 23 1976 2016 2008 2007 normal 2012,2013 5 58.2 59.4 -1.2 16 44 1992 2016 1997 2008 bottom-third 6 59.7 60.9 -1.2 17 43 1992 2016 1997 2008 bottom-third 1964,1981,1982 7 59.5 60.6 -1.1 16 44 1992 2016 2003 2008 bottom-third 1965,1966,1978 8 57.9 59.0 -1.1 20 40 1992 2010 2003 2008 bottom-third 1995 9 55.6 56.4 -0.8 23 37 1992 2012 2003 2008 normal 1984 10 52.8 53.4 -0.6 34 26 1967,1978 2012 2008 2007 normal 1968,1975,1988,2002 11 49.6 50.7 -1.1 23 37 1978,2014 2012 2003 2008 normal 1985,2015,2019 12 47.6 49.0 -1.4 20 40 1978,2014 2012 2003 2008 bottom-third 1980,1984 18 52.0 53.0 -1.0 23 36 1978 2012 2003 2008 normal 1990 24 47.9 49.0 -1.1 24 35 1979 2017 2004 2008 normal 1985,2004 36 48.8 48.9 -0.1 39 19 1980 2012 2005 2008 top-third 1975 48 49.0 48.9 0.1 41 16 1981 2013 2006 2008 top-third 2011 60 49.1 48.9 0.2 42 14 1982 2002,2013,2020 2007 2008 top-third 2007,2017