1991-2020 Degrees Fahrenheit 1 68.1 65.8 2.3 76 3 1964 1981 2007 2006 top-tenth 2 66.0 64.4 1.6 71 8 1964 2014 2007 2006 top-tenth 3 64.8 63.2 1.6 71 8 1967 2014 2007 2004 top-tenth 1996 4 63.5 62.0 1.5 72 7 1964 2014 2007 2004 top-tenth 5 62.1 61.1 1.0 70 9 1950 2014 2007 2004 top-third 2004,2013,2017 6 61.0 60.5 0.5 65 14 1950 2014 2007 2004 top-third 2017 7 60.2 60.0 0.2 60 19 1950 2014 2007 2006 top-third 8 60.4 60.3 0.1 63 16 1949 2014 2007 2006 top-third 1984,2004 9 61.0 60.9 0.1 61 18 1949 2014 2007 2006 top-third 1994,2021 10 61.7 61.8 -0.1 63 16 1949 2014,2016 2007 2006 top-third 1978,1981,1993,1994,2006,2019 11 62.5 62.5 0.0 62 17 1949 2016 2007 2004 top-third 12 63.1 63.1 0.0 62 16 1949 2016 2007 2004 top-third 1992 18 61.9 62.2 -0.3 56 22 1950 2015 2003 2007 top-third 24 63.1 63.0 0.1 65 12 1950 2016 2007 1998 top-third 1994,1998 36 63.0 63.0 0.0 64 12 1950 2016 2007 1998 top-third 1997,2009 48 62.9 62.9 0.0 65 10 1951,1952 2017,2018 2007 2007 top-third 1994,1995,1996,1997,1998,2007,2014 60 63.0 62.9 0.1 65 9 1952,1953 2018 2007 1997 top-third 1996,1997