1925-2000 Degrees Fahrenheit 1 13.7 11.7 2.0 56 43 1963 2002 2012 2010 normal 2 23.9 18.6 5.3 86 13 1956 2002 2012 2002 top-third 3 29.1 25.9 3.2 78 21 1956 2002 2012 2010 top-third 4 34.7 31.8 2.9 83 16 1956 1979 2012 2010 top-third 2017 5 38.7 36.0 2.7 87 12 1948,1956 2019 2012 2007 top-third 1925 6 41.3 38.2 3.1 91 8 1955 2019 2012 2007 top-tenth 1957 7 40.4 38.1 2.3 83 16 1955 2019 2012 2010 top-third 2010 8 37.4 36.3 1.1 67 32 1955 2019 2012 2010 top-third 1937,1953,2009 9 34.5 33.5 1.0 64 35 1927 2019 2012 2010 normal 10 31.7 30.6 1.1 63 36 1955 2019 2012 2010 normal 11 29.7 28.0 1.7 72 27 1971 2019 2012 2010 top-third 1987 12 27.2 26.0 1.2 67 31 1971 2019 2012 2010 top-third 1941,2020 18 30.6 30.0 0.6 59 39 1956 2019 2012 2011 normal 1931,1953,1997,2000,2008 24 26.2 25.9 0.3 43 54 1956 2019 2012 2011 normal 1984,1986 36 26.1 26.0 0.1 40 56 1973 2016 1992 2012 normal 1929,1969 48 26.7 25.9 0.8 55 40 1974 2019 2012 2010 normal 1983,2009 60 26.6 25.9 0.7 51 43 1975 2019 2012 2011 normal 1930,1946,1988