1991-2020 Degrees Fahrenheit 1 53.0 51.7 1.3 55 25 1976 1985 2014 2015 top-third 2 58.8 56.8 2.0 73 7 1976 1985 2015 2007 top-tenth 3 64.7 62.1 2.6 78 2 1976 1985 2015 1985 top-tenth 4 69.1 66.4 2.7 78 2 1976 2007 2015 2007 top-tenth 5 71.7 69.2 2.5 79 1 1967 2016 2015 2016 highest 6 72.6 70.5 2.1 78 2 1967 2010 2015 2010 top-tenth 7 71.9 70.3 1.6 77 2 1967 2010 2015 2010 top-tenth 8 70.5 69.2 1.3 76 3 1967 2010 2015 2011 top-tenth 9 69.2 67.3 1.9 77 2 1967 2010 2015 2010 top-tenth 10 66.7 65.1 1.6 78 1 1967 2016 2015 2016 highest 11 64.2 63.0 1.2 75 4 1967 1990,2017 2015 1990 top-tenth 12 63.5 61.5 2.0 78 1 1967 2016 2015 2016 highest 18 66.1 64.5 1.6 77 2 1967 2017 2015 2016 top-tenth 24 62.3 61.5 0.8 75 3 1967 2017 2015 1991 top-tenth 1991 36 61.5 61.4 0.1 61 16 1969 2018 2015 2012 top-third 1999 48 61.1 61.4 -0.3 55 21 1969 2019 2015 2014 top-third 1991,2003,2006,2014 60 61.4 61.4 0.0 60 15 1967 2020 2015 2013 top-third 2006