1991-2020 Degrees Fahrenheit 1 43.3 44.3 -1.0 34 44 1976 1999 2019 2021 normal 1989 2 51.0 50.8 0.2 44 34 1976 1963 2020 2021 normal 2006,2020 3 57.9 57.0 0.9 57 21 1976 1963 2020 2021 top-third 1960 4 63.3 62.3 1.0 59 19 1976 1963 2020 2021 top-third 5 66.9 65.8 1.1 60 17 1967 1954 2020 2021 top-third 1953,1990,2005,2012 6 68.7 67.4 1.3 63 14 1951 1963 2020 2021 top-third 1990,2007 7 68.6 67.2 1.4 67 10 1976 1963 2021 2016 top-third 2011 8 66.9 65.8 1.1 68 9 1951 1963 2021 2016 top-third 1956,2006 9 64.5 63.5 1.0 64 13 1951 2012 2020 2021 top-third 1991,2015 10 61.3 60.7 0.6 60 17 1951 2012 2021 2017 top-third 1953,2011 11 58.5 57.9 0.6 59 18 1979 2012 2021 2017 top-third 12 57.2 55.9 1.3 71 6 1979 2012 2021 2016 top-tenth 1998,2007 18 61.3 59.8 1.5 70 6 1951 2012 2021 2017 top-tenth 24 56.9 55.9 1.0 66 10 1979 2017 2021 2017 top-third 36 56.7 55.9 0.8 67 8 1979 2017 2021 2018 top-third 48 56.3 55.9 0.4 61 13 1951 2018 2021 2019 top-third 1956,2008 60 56.2 55.9 0.3 61 12 1962 2016 2021 2021 top-third 2008,2013,2015,2021