1991-2020 Degrees Fahrenheit 1 68.2 67.0 1.2 109 19 1936 2005 2013 2012 top-third 2 62.6 62.3 0.3 97 30 1917 1991 2009 2013 top-third 2016 3 56.9 57.0 -0.1 93 33 1917 1991 2013 2013 top-third 2013,2018 4 49.3 51.5 -2.2 48 76 1926 2012 1997 2013 normal 1938 5 43.2 46.7 -3.5 24 100 1917 2012 1996 2013 bottom-third 1905,1906,1960,1996 6 39.4 43.3 -3.9 23 99 1917 2012 1982 2013 bottom-third 7 37.5 41.6 -4.1 19 103 1904,1917 2012 1979 2013 bottom-third 1947 8 37.8 41.4 -3.6 21 101 1904 2012 1996 2013 bottom-third 9 39.5 42.5 -3.0 25 97 1918 2012 1996 2013 bottom-third 1994 10 41.9 44.6 -2.7 27 95 1918 2012 1996 2013 bottom-third 11 44.4 46.9 -2.5 30 92 1918 2012 1996 2013 bottom-third 1929,1935,1959 12 46.7 49.0 -2.3 35 87 1918 2012 1997 2013 bottom-third 1966,2015 18 45.3 47.1 -1.8 56 60 1918 2017 1997 2013 normal 1919 24 48.1 48.9 -0.8 81 35 1918 2017 2009 2013 top-third 2009 36 49.6 48.9 0.7 104 8 1918 2018 2011 2013 top-tenth 2001,2007,2008,2021 48 49.5 48.9 0.6 99 9 1918,1926,1927 2013,2019 2011 2013 top-tenth 2007,2021 60 49.4 48.9 0.5 98 7 1927 2020 2011 2013 top-tenth 2019