1991-2020 Degrees Fahrenheit 1 38.4 37.4 1.0 56 29 1979 2017 2015 2012 normal 2 35.7 36.3 -0.6 49 36 1978 2023 2015 2013 normal 1995 3 40.4 37.4 3.0 78 7 1963 2023 2015 2012 top-tenth 4 43.3 39.9 3.4 79 5 1977 2012,2023 2015 2012 top-tenth 5 45.9 43.6 2.3 78 6 1977 2017 2015 2012 top-tenth 6 50.4 48.0 2.4 80 4 1977 2017 2015 2012 top-tenth 2020 7 54.0 52.1 1.9 78 6 1977 2017 2015 2012 top-tenth 2002 8 57.0 55.5 1.5 78 6 1977 2017 2015 2012 top-tenth 9 59.0 57.6 1.4 77 6 1977 2017 2015 2012 top-tenth 10 60.1 58.3 1.8 78 5 1977 2012 2015 2012 top-tenth 11 59.7 58.1 1.6 78 5 1977 2012 2015 2012 top-tenth 12 58.1 57.0 1.1 75 8 1977 2012 2015 2013 top-tenth 18 53.9 54.0 -0.1 60 22 1941 2017 2015 2013 top-third 24 56.4 57.0 -0.6 54 27 1964,1968 2013 2015 2014 top-third 1993,2005 36 56.1 57.0 -0.9 42 37 1963,1968,1979 2013 1996 2015 normal 1974,1990 48 56.8 56.9 -0.1 58 19 1964 2023 2006 2015 top-third 2000,2001 60 57.3 56.9 0.4 65 10 1965,1968 2023 2011 2015 top-third 2011,2017,2019