1991-2020 Degrees Fahrenheit 1 59.1 57.8 1.3 52 30 1967 1977 2005 2001 normal 2 55.2 51.5 3.7 76 6 1947 1977 2005 1998 top-tenth 3 48.0 45.0 3.0 73 9 1950 2012 2005 2000 top-third 4 40.8 38.9 1.9 72 10 1950 2012 2005 2000 top-third 1985,2017 5 38.3 34.4 3.9 76 5 2014 2012 2005 1998 top-tenth 6 35.3 32.5 2.8 75 6 2014 2012 2005 2000 top-tenth 2000 7 35.4 32.8 2.6 70 9 2014 2012 2005 2002 top-third 8 37.4 34.7 2.7 73 6 2014 2012 2005 2002 top-tenth 1999,2010,2017 9 40.4 37.7 2.7 74 5 1943 2016 2005 1999 top-tenth 10 43.5 40.9 2.6 74 5 1943 2012 2005 1999 top-tenth 11 46.2 43.6 2.6 76 3 1943 2012 2005 1999 top-tenth 1999 12 48.4 45.6 2.8 76 3 1943 2012 2005 2006 top-tenth 18 43.2 41.2 2.0 72 6 1951 1999 2005 2000 top-tenth 24 47.0 45.6 1.4 69 7 1952,1979 2017 2005 2000 top-tenth 36 46.6 45.6 1.0 65 9 1979 2000 2005 2002 top-third 48 46.1 45.6 0.5 61 11 1968 2001,2002 2005 2003 top-third 60 46.4 45.6 0.8 67 3 1969 2002 2005 2003 top-tenth 2020