1991-2020 Degrees Fahrenheit 1 33.6 33.3 0.3 52 33 1965 2012 2005 2004 normal 2 26.8 27.0 -0.2 58 27 1965 2012 2003 2005 top-third 1984 3 27.4 23.4 4.0 76 9 1979 2012 2005 2000 top-third 4 25.4 23.0 2.4 73 12 2014 2012 2005 2002 top-third 5 27.6 25.4 2.2 73 12 1951 2012 2005 2002 top-third 6 31.8 29.4 2.4 75 10 2014 2012 2005 2002 top-third 7 36.7 34.3 2.4 76 9 1951,1978 2012 2005 2002 top-third 8 41.1 39.0 2.1 78 7 1978 2012 2005 2002 top-tenth 9 45.0 42.9 2.1 78 7 1951 2012 2005 2002 top-tenth 10 47.9 45.6 2.3 79 6 1951 2012 2005 2002 top-tenth 11 48.6 46.9 1.7 78 7 1951 2012 2005 2002 top-tenth 12 48.9 46.9 2.0 78 7 1951 2012 2005 2002 top-tenth 18 42.8 41.0 1.8 77 7 1951,1952 2017 2005 2000 top-tenth 24 47.9 46.9 1.0 76 8 1952 2017 2005 2000 top-tenth 1988 36 47.5 46.9 0.6 74 9 1952 2018 2005 2002 top-third 2001,2002,2019,2022 48 47.1 46.9 0.2 67 15 1953 2013,2019 2005 2005 top-third 2003,2005 60 47.5 46.9 0.6 78 3 1952 2020 2005 2003 top-tenth 2003,2008,2013,2016,2019