1991-2020 Degrees Fahrenheit 1 4.9 5.1 -0.2 61 34 1912 2006 2000 2002 normal 2 11.1 8.2 2.9 75 16 1918 2006 2001 2002 top-third 2000 3 15.1 14.2 0.9 71 18 1920 2002 2001 2002 top-third 1983 4 19.6 21.0 -1.4 53 35 1920 2016 1997 2002 normal 1992 5 27.1 27.7 -0.6 58 28 1920 2016 1997 2002 top-third 6 33.2 33.6 -0.4 62 23 1920 2016 1997 2002 top-third 1975,1988,2008 7 38.3 38.0 0.3 67 18 1920 2016 2001 2002 top-third 1975,2001 8 41.4 40.9 0.5 66 17 1986 2016 2001 2002 top-third 9 41.9 42.0 -0.1 58 25 1951 2002 1997 2002 top-third 2015 10 41.5 41.7 -0.2 56 27 1951 2002 1997 2002 top-third 1949,1981,1987 11 39.1 40.0 -0.9 47 34 1951 2002,2016,2022 1997 2002 normal 1981,2010 12 37.4 37.5 -0.1 59 22 1951 1999 1997 2002 top-third 1921,1974,1982,1987,2008 18 37.6 36.2 1.4 70 9 1951 2017 1998 2002 top-third 2006,2021 24 38.6 37.5 1.1 64 12 1952 2000 1998 2002 top-third 36 38.8 37.4 1.4 65 6 1952 2001 1999 2002 top-tenth 2008 48 39.1 37.4 1.7 63 3 1952 2002 2000 2002 top-tenth 60 39.3 37.3 2.0 60 2 1970 2002 2001 2002 top-tenth