1991-2020 Degrees Fahrenheit 1 41.3 33.3 8.0 83 3 1965 2012 2015 2012 top-tenth 2 33.2 27.0 6.2 82 4 1965 2012 2015 2012 top-tenth 3 28.0 23.4 4.6 78 8 2014 2012 2015 2012 top-tenth 4 28.6 23.0 5.6 83 3 2014 2012 2015 2012 top-tenth 5 31.2 25.4 5.8 84 2 1951 2012 2015 2012 top-tenth 6 34.6 29.4 5.2 84 2 2014 2012 2015 2012 top-tenth 7 39.4 34.3 5.1 84 2 1978 2012 2015 2012 top-tenth 8 43.3 39.0 4.3 84 2 1978 2012 2015 2012 top-tenth 9 46.6 42.9 3.7 84 2 1978 2012 2015 2012 top-tenth 2017 10 49.0 45.6 3.4 84 2 1951,1978 2012 2015 2012 top-tenth 2017 11 49.9 46.8 3.1 83 3 1951 2012 2015 2012 top-tenth 12 49.9 46.9 3.0 83 3 1951 2012 2015 2012 top-tenth 18 42.4 41.0 1.4 75 10 1952 2017 2015 2013 top-third 24 47.6 46.9 0.7 74 11 1952 2017 2015 2013 top-third 2023 36 46.2 46.9 -0.7 54 30 1952 2018 2015 2014 normal 1983,1987,2011 48 46.6 46.9 -0.3 56 27 1952,1953,1968,1970 2013,2019 2011 2015 top-third 60 47.5 46.9 0.6 79 3 1952,1970 2020 2015 2013 top-tenth 2006,2008,2013,2019