1991-2020 Degrees Fahrenheit 1 40.2 35.6 4.6 75 9 1979 2017 2001 1998 top-third 2 39.3 34.5 4.8 78 6 1978 2023 2001 1998 top-tenth 3 40.5 35.8 4.7 82 2 1977 2016 2001 2002 top-tenth 2023 4 43.4 38.6 4.8 81 2 1977 2016 2001 2002 top-tenth 5 46.3 42.4 3.9 81 2 1977 2016 2001 2002 top-tenth 6 49.9 46.9 3.0 80 3 1977 2016 2001 2002 top-tenth 7 54.0 51.2 2.8 79 4 1977 2016 2001 2002 top-tenth 8 56.6 54.5 2.1 77 6 1977 2016 2001 2002 top-tenth 2022 9 58.6 56.6 2.0 76 6 1977 2016 2001 2002 top-tenth 2022 10 59.1 57.3 1.8 75 7 1977 2016 2001 2002 top-tenth 11 58.6 57.0 1.6 75 7 1977 2016 2001 2002 top-tenth 12 57.1 55.9 1.2 72 9 1963 2017 2001 2002 top-third 2011 18 52.9 52.9 0.0 60 20 1978 2017 2001 2000 top-third 24 55.6 55.8 -0.2 57 21 1964 2017 2001 2000 top-third 36 55.7 55.8 -0.1 58 17 1963 2018 2001 2000 top-third 48 56.0 55.7 0.3 57 15 1964 2023 2001 2002 top-third 2011 60 55.8 55.7 0.1 52 17 1965,1970 2020 2001 2002 top-third 2003