1991-2020 Degrees Fahrenheit 1 50.5 53.2 -2.7 34 90 1919 1950 2009 2012 bottom-third 1939 2 59.4 60.2 -0.8 80 44 1912 2015 2009 2012 normal 1921,1958 3 65.0 65.5 -0.5 93 31 1912 2015 2009 2012 top-third 4 68.9 69.0 -0.1 100 24 1912 2003 2009 2012 top-third 5 70.4 69.8 0.6 108 16 1912 2018 2011 2012 top-third 6 69.2 68.5 0.7 112 12 1912 2018 2011 2012 top-tenth 2015,2016 7 66.5 66.1 0.4 108 16 1912 2018 2011 2012 top-third 8 63.8 63.5 0.3 108 16 1912 2012 2011 2012 top-third 9 60.4 60.3 0.1 105 19 1917 2012,2018 2011 2012 top-third 10 56.0 57.1 -1.1 91 33 1917 2012,2018 2011 2012 top-third 1997,2019 11 53.4 54.4 -1.0 86 37 1917 2018 2010 2012 top-third 1972,1983 12 52.6 53.2 -0.6 97 26 1917 2018 2011 2012 top-third 1977,1999,2004 18 58.6 58.3 0.3 112 11 1917 2018 2011 2012 top-tenth 24 53.8 53.2 0.6 112 10 1913,1917 2018 2012 2003 top-tenth 2015 36 53.3 53.2 0.1 103 18 1917 2018 2012 2007 top-third 48 52.8 53.1 -0.3 97 23 1920 2018 2012 2012 top-third 1996,2012 60 52.8 53.1 -0.3 98 21 1917 2018,2019,2021 2012 2009 top-third 1997