1991-2020 Degrees Fahrenheit 1 68.2 68.1 0.1 56 29 1976 2004 2009 2010 normal 2 73.8 73.5 0.3 60 25 1976 2016 2009 2010 top-third 3 80.0 77.2 2.8 84 1 1976 2011 2010 2011 highest 4 82.2 79.1 3.1 84 1 1976 2011 2010 2011 highest 5 83.0 79.6 3.4 83 1 1976 2011 2010 2011 highest 6 81.5 78.8 2.7 82 2 1976 1998 2010 1998 top-tenth 7 80.1 77.1 3.0 83 1 1976 2011 2010 2011 highest 8 77.7 74.9 2.8 83 1 1976 2011 2010 2011 highest 9 74.8 72.4 2.4 83 1 1940 2011 2010 2011 highest 10 71.8 70.0 1.8 79 5 1940 2012 2010 1998 top-tenth 11 69.7 68.2 1.5 79 5 1940 2016 2010 2011 top-tenth 12 68.7 67.3 1.4 79 5 1940 2016 2010 2000 top-tenth 2022 18 72.9 71.1 1.8 79 4 1977 2012,2016 2010 2011 top-tenth 24 67.9 67.3 0.6 74 9 1961,1979 2017 2010 2006 top-third 2019,2022 36 67.3 67.3 0.0 67 15 1961 2018 2010 2008 top-third 2001 48 67.2 67.2 0.0 63 18 1961 2018,2019 2010 2009 top-third 2005,2009 60 67.3 67.2 0.1 63 17 1962 2019,2020 2010 2009 top-third 2001,2009