1991-2020 Degrees Fahrenheit 1 74.2 71.9 2.3 114 14 1924 2012 2005 2002 top-third 2 70.8 69.7 1.1 108 20 1929 2012 2004 2005 top-third 2021 3 66.4 65.8 0.6 102 25 1924 2012 2004 2005 top-third 1970,2013 4 62.3 61.0 1.3 115 11 1917 2012 2004 2005 top-tenth 5 57.3 56.0 1.3 113 11 1926 2012 2005 1999 top-tenth 2021 6 52.4 51.3 1.1 112 12 1917 2012 2005 2005 top-tenth 2005 7 50.0 47.7 2.3 116 6 1917 2012 2005 1998 top-tenth 1991 8 47.3 45.7 1.6 112 10 1904 2012 2005 1999 top-tenth 2020 9 46.8 45.2 1.6 112 10 1904 2012 2005 2002 top-tenth 2000 10 47.5 45.9 1.6 113 9 1904 2012 2005 2002 top-tenth 2010 11 49.3 47.5 1.8 116 6 1904,1918 2012 2005 1999 top-tenth 12 51.2 49.4 1.8 116 6 1904 2012 2005 1999 top-tenth 18 51.6 50.0 1.6 113 5 1918 2012 2005 1999 top-tenth 24 50.4 49.4 1.0 107 9 1918 2017 2005 2000 top-tenth 36 50.1 49.4 0.7 102 10 1918 2012 2005 2001 top-tenth 48 49.6 49.3 0.3 95 13 1918 2013 2005 2002 top-third 2014 60 49.8 49.3 0.5 97 8 1927 2002 2005 2003 top-tenth 2010,2014,2022