1991-2020 Degrees Fahrenheit 1 54.1 45.9 8.2 76 2 1960 2012 2006 2007 top-tenth 2 42.1 40.5 1.6 63 15 1960 2012 2006 2005 top-third 2005 3 38.0 37.2 0.8 58 20 1979 2012 2005 2006 top-third 2005 4 38.4 36.4 2.0 71 7 1979 2012 2006 2000 top-tenth 1987 5 40.0 38.0 2.0 70 8 1979 2012 2006 2006 top-tenth 2006 6 42.6 41.2 1.4 66 12 1979 2012 2005 2006 top-third 1995,2005 7 46.0 45.3 0.7 62 16 1979 2016 2004 2006 top-third 8 50.4 49.4 1.0 67 11 1979 2012 2005 2006 top-third 1991,2023 9 53.9 52.8 1.1 64 13 1979 2012 2005 2006 top-third 10 56.2 55.1 1.1 64 13 1962,1979 2012 2005 2006 top-third 2023 11 57.1 56.1 1.0 64 13 1962 2012 2005 2006 top-third 12 57.5 56.1 1.4 68 9 1962 2012 2006 2002 top-third 18 52.7 51.1 1.6 72 5 1979 2017 2006 2000 top-tenth 24 57.4 56.0 1.4 71 5 1979 2013,2017 2006 2000 top-tenth 36 57.0 56.0 1.0 71 4 1979 2013 2006 2007 top-tenth 48 56.8 56.0 0.8 70 4 1980 2002 2006 2002 top-tenth 60 56.6 56.0 0.6 67 6 1962 2003 2005 2006 top-tenth 2008,2017,2019