1991-2020 Degrees Fahrenheit 1 59.9 59.8 0.1 55 30 1988 2007 2018 2019 normal 2 65.5 65.4 0.1 60 24 1940 2007 2013 2019 top-third 1970 3 70.2 69.6 0.6 69 15 1940 2005,2007 2019 2019 top-third 1998,2019 4 73.4 72.0 1.4 78 6 1940 2016 2019 2018 top-tenth 2018 5 73.9 72.3 1.6 78 6 1940 2010 2019 2016 top-tenth 6 71.7 70.9 0.8 74 10 1940 2010 2019 2018 top-third 7 68.7 68.5 0.2 71 13 1940 2010 2019 2019 top-third 2013,2019 8 66.1 65.3 0.8 76 8 1940 2010 2019 2016 top-tenth 9 63.2 62.1 1.1 79 5 1940 2010,2012 2019 2017 top-tenth 2017,2021 10 60.8 59.4 1.4 79 5 1940 2012 2019 2017 top-tenth 1991,1998,2017 11 58.8 57.6 1.2 75 9 1940 2012 2019 2017 top-third 2006,2021 12 57.6 56.9 0.7 72 12 1940 2012 2019 2017 top-third 18 62.1 61.6 0.5 72 11 1948 2016 2019 2017 top-third 1999,2010,2011 24 57.0 56.9 0.1 66 17 1941 2017 2019 2018 top-third 1998 36 57.0 56.9 0.1 66 16 1942 2012 2016 2019 top-third 2009 48 57.3 56.9 0.4 72 9 1943 2013 2017 2019 top-third 2002,2009,2021 60 57.8 56.8 1.0 79 1 1944 2020 2019 2020 highest