1991-2020 Degrees Fahrenheit 1 50.5 45.1 5.4 100 8 2018 1915 1940 1941 top-tenth 2 42.1 38.2 3.9 95 13 1965 2012 1941 1910 top-third 2004 3 33.9 31.7 2.2 85 23 1965,2014 2012 1941 1938 top-third 4 29.6 27.4 2.2 92 15 1979 2012 1941 1931 top-third 2005 5 28.8 26.0 2.8 96 11 1979 2012 1941 1931 top-tenth 6 29.8 27.2 2.6 96 11 1979 2012 1941 1931 top-tenth 1919 7 32.6 30.2 2.4 97 10 1979 2012 1941 1931 top-tenth 1919 8 36.3 34.0 2.3 96 10 1979 2012 1941 1932 top-tenth 1987,1998 9 40.1 37.8 2.3 98 7 1979 2012 1941 1931 top-tenth 1999 10 43.3 41.1 2.2 97 8 1979 2012 1941 1932 top-tenth 2000 11 45.5 43.4 2.1 97 8 1979 2012 1941 1932 top-tenth 12 46.9 44.6 2.3 100 5 1979 2012 1941 1931 top-tenth 18 40.0 38.8 1.2 91 13 1918 2017 1941 1932 top-third 24 45.7 44.6 1.1 93 9 1918 2017 1941 1932 top-tenth 1915 36 45.5 44.6 0.9 89 10 1918 2017 1941 1933 top-tenth 2008 48 45.2 44.6 0.6 86 11 1980 1934 1941 1935 top-third 2005,2006 60 45.2 44.6 0.6 85 10 1997 1935 1941 1935 top-third 2003,2007,2012