1991-2020 Degrees Fahrenheit 1 41.8 34.8 7.0 82 4 1959 2001 1998 1999 top-tenth 2 45.7 42.2 3.5 77 9 1959 1963 1998 1994 top-tenth 3 51.1 49.3 1.8 73 13 1951 2016 1997 1998 top-third 4 56.1 54.9 1.2 70 16 1951 2016 1997 1998 top-third 1994,2013 5 60.3 58.8 1.5 74 12 1951 2016 1997 1998 top-third 1983,2007 6 61.6 60.6 1.0 71 15 1951 2021 1998 1998 top-third 1983,1988,1998 7 61.5 60.5 1.0 70 16 1945 2021 1997 1998 top-third 1987 8 60.1 58.8 1.3 71 15 1945 2021 1997 1998 top-third 2006 9 57.3 56.0 1.3 73 12 1951 2012,2021 1997 1998 top-third 10 54.4 52.4 2.0 78 7 1951 2012 1997 1998 top-tenth 2005 11 50.7 49.2 1.5 75 10 1951 2012 1997 1998 top-third 1990,2007 12 48.6 46.9 1.7 77 8 1951 2012 1997 1998 top-tenth 18 52.9 51.5 1.4 77 8 1951 2012 1997 1998 top-tenth 2007 24 49.3 46.9 2.4 82 2 1951 2017 1998 1999 top-tenth 36 47.7 46.9 0.8 74 9 1952 2017 1998 1999 top-third 48 46.7 46.9 -0.2 59 23 1952 2018 1998 1990 top-third 2016 60 46.7 46.9 -0.2 55 26 1952 2002 1998 1991 top-third