1991-2020 Degrees Fahrenheit 1 45.0 47.6 -2.6 32 97 1920 1981 1997 1998 bottom-third 2 43.4 43.9 -0.5 92 37 1912 2012 1998 1994 top-third 2011,2014 3 42.0 39.7 2.3 115 12 1899 2012 1998 1992 top-tenth 4 39.8 36.9 2.9 120 5 1912 1992 1998 1992 top-tenth 5 37.3 35.1 2.2 118 6 1912 1992 1998 1992 top-tenth 6 38.0 35.5 2.5 116 5 1912 2000 1998 1992 top-tenth 7 39.7 37.6 2.1 113 6 1912 2000 1998 1992 top-tenth 8 43.4 40.9 2.5 114 4 1912 1981 1998 1981 top-tenth 9 46.9 44.4 2.5 116 2 1912 1981 1998 1981 top-tenth 2000 10 49.8 47.6 2.2 115 3 1912 1981 1998 1981 top-tenth 11 51.1 49.5 1.6 110 7 1912 1981 1998 1992 top-tenth 2017 12 51.9 50.2 1.7 113 4 1912 1981 1998 1992 top-tenth 1934,2022 18 46.6 45.3 1.3 108 4 1909,1916 2000 1998 1935 top-tenth 2001,2004 24 51.1 50.2 0.9 104 6 1909 2000 1998 1992 top-tenth 1992,2003,2022 36 50.4 50.2 0.2 90 16 1918 2000 1998 1992 top-third 1935,1955,1983,2022 48 49.9 50.3 -0.4 80 22 1918 2002 1998 1992 top-third 1956,1983,1990,1991 60 50.2 50.3 -0.1 82 16 1912,1918,1920 2003 1998 1992 top-third 2019