1991-2020 Degrees Fahrenheit 1 33.2 34.7 -1.5 45 40 1977 2023 2018 2017 normal 2 36.9 37.5 -0.6 52 33 1977 2016 2018 2017 normal 3 39.8 41.4 -1.6 44 41 1977 2002,2016 2018 2017 normal 1960 4 44.8 46.0 -1.2 44 41 1977 2002 2015 2018 normal 2011,2015 5 50.4 51.0 -0.6 55 29 1977 2016 2015 2018 normal 1960,1962 6 55.5 55.5 0.0 67 17 1977 2016 2018 2017 top-third 1950,1992,2020 7 59.0 58.8 0.2 65 19 1977 2016 2018 2017 top-third 1950 8 60.7 60.7 0.0 63 21 1977 2016,2017 2018 2017 top-third 1972 9 61.5 61.0 0.5 68 16 1941,1977 2016 2018 2017 top-third 2000 10 60.3 60.3 0.0 66 18 1941 2016 2018 2017 top-third 1950 11 58.5 58.8 -0.3 63 21 1941 2007,2017 2018 2017 top-third 2005 12 57.2 56.9 0.3 68 16 1941 2013,2017 2018 2017 top-third 1991 18 56.3 56.4 -0.1 63 20 1945,1964 2017 2015 2018 top-third 2020 24 57.1 56.9 0.2 67 16 1942 2007,2013 2016 2018 top-third 2011 36 57.7 56.8 0.9 76 6 1943 2013 2017 2018 top-tenth 2022 48 57.7 56.8 0.9 78 3 1944 2013,2014 2018 2014 top-tenth 2008,2023 60 57.2 56.8 0.4 68 12 1945 2021 2018 2017 top-third 2002,2003,2012