1991-2020 Degrees Fahrenheit 1 35.6 36.5 -0.9 29 43 1959 2001 2014 2016 normal 2 44.4 43.2 1.2 46 26 1976 1963 2014 2016 normal 1982 3 51.3 49.6 1.7 57 15 1976 2016 2014 2016 top-third 1958 4 55.0 54.7 0.3 39 32 1976 2016 2014 2016 normal 2003,2011 5 58.2 58.1 0.1 34 37 1992 2016 2014 2016 normal 1966,2000,2008 6 60.1 59.8 0.3 42 29 1992 2016 2014 2016 normal 1960,1987 7 59.7 59.7 0.0 38 33 1992 2016 2014 2016 normal 1965,1990 8 58.6 58.2 0.4 44 27 1992 2016 2014 2016 normal 1994 9 56.1 55.6 0.5 47 24 1951 2012,2016 2014 2016 normal 1994 10 53.9 52.4 1.5 63 8 2014 2012,2016 2015 2016 top-third 1977,1999 11 51.1 49.3 1.8 65 5 2014 2012 2015 2016 top-tenth 1973,2005 12 48.6 47.2 1.4 62 8 2014 2012 2015 2016 top-third 2007,2020,2021 18 53.5 51.4 2.1 66 3 2014 2016 2015 2016 top-tenth 24 49.6 47.2 2.4 67 1 1979 2017 2016 2017 highest 36 48.9 47.2 1.7 64 2 1979 2000 2016 2000 top-tenth 48 47.4 47.2 0.2 46 18 1979 2001 2016 2013 top-third 1957,2003 60 47.2 47.2 0.0 42 20 1979 2002 2015 2016 top-third 2009,2012,2018