1991-2020 Degrees Fahrenheit 1 59.3 58.1 1.2 67 13 1948 2015 2006 2004 top-third 2 58.1 57.5 0.6 69 11 1949 2015 2006 1997 top-third 1984 3 56.7 57.3 -0.6 51 29 1949 2015 2006 2005 normal 1968,1970 4 56.7 57.1 -0.4 56 24 1949 2015 2006 2006 top-third 1970,2006 5 57.9 57.9 0.0 66 14 1949 2015 2006 2006 top-third 1980,1981,1996,2006,2009 6 59.1 59.3 -0.2 60 20 1949 2015 2006 2003 top-third 2010 7 60.4 60.6 -0.2 60 20 1949 2015 2006 2003 top-third 1992,2003 8 61.6 61.7 -0.1 64 16 1949 2015 2006 1998 top-third 1968 9 63.0 62.5 0.5 69 10 1949 2015 2006 2007 top-third 10 63.5 62.7 0.8 69 10 1949 2015 2006 2007 top-third 11 63.5 62.7 0.8 69 10 1949 2015 2006 2007 top-third 12 63.1 62.5 0.6 67 12 1949 2015 2006 1998 top-third 2009 18 61.7 61.4 0.3 68 11 1949 2015 2006 2007 top-third 2009 24 62.5 62.4 0.1 62 16 1950 2016 2006 1998 top-third 36 62.4 62.4 0.0 64 13 1950,1951 2016 2006 1995 top-third 1995 48 62.2 62.3 -0.1 63 13 1952 2018 2006 1998 top-third 1998,2014 60 62.1 62.3 -0.2 58 17 1952,1953 2018 2006 1998 top-third 1995,2013