1991-2020 Degrees Fahrenheit 1 30.7 30.1 0.6 55 23 1979 2006 2019 2021 top-third 2 36.9 31.8 5.1 75 3 1984 1992 2021 1992 top-tenth 3 40.3 35.9 4.4 76 2 1977 2002 2021 2002 top-tenth 4 45.3 41.2 4.1 77 1 1977 2022 2021 2022 highest 5 50.9 46.8 4.1 77 1 1977 2022 2021 2022 highest 6 55.6 52.0 3.6 77 1 1977 2022 2021 2022 highest 7 58.9 55.9 3.0 76 1 1977 2022 2021 2022 highest 8 61.2 58.4 2.8 76 1 1977 2022 2021 2022 highest 9 61.4 59.2 2.2 74 3 1977 2013 2021 2013 top-tenth 10 60.8 58.8 2.0 72 5 1962 2013 2021 2017 top-tenth 11 59.8 57.6 2.2 74 3 1962 2013 2021 2017 top-tenth 12 56.7 55.7 1.0 67 10 1979 2013 2021 2018 top-third 2007 18 55.4 54.4 1.0 67 10 1979 2013 2021 2018 top-third 24 56.6 55.6 1.0 68 8 1962 2013 2021 2018 top-tenth 1955,2012 36 56.2 55.6 0.6 65 10 1963 2013 2021 2019 top-third 2007,2015 48 56.1 55.6 0.5 61 13 1962 2019 2017 2021 top-third 60 56.3 55.6 0.7 66 7 1963 2017 2018 2021 top-tenth 2003