1991-2020 Degrees Fahrenheit 1 57.2 57.8 -0.6 44 38 1967 1977 2020 2018 normal 2009 2 52.5 51.5 1.0 61 21 1947 1977 2020 2016 top-third 3 47.7 45.0 2.7 72 10 1950 2012 2020 2016 top-third 4 38.9 38.9 0.0 60 22 1950 2012 2019 2020 top-third 5 35.5 34.4 1.1 68 13 2014 2012 2019 2020 top-third 6 33.9 32.5 1.4 68 13 2014 2012 2019 2020 top-third 7 34.8 32.8 2.0 68 11 2014 2012 2020 2017 top-third 8 35.8 34.7 1.1 68 11 2014 2012 2020 2017 top-third 2007 9 38.4 37.7 0.7 66 13 1943 2016 2020 2017 top-third 10 41.7 40.9 0.8 68 11 1943 2012 2020 2017 top-third 11 44.6 43.6 1.0 68 11 1943 2012 2020 2017 top-third 12 46.7 45.6 1.1 69 10 1943 2012 2020 2017 top-third 1987 18 42.5 41.2 1.3 68 10 1951 1999 2020 2017 top-third 24 46.4 45.6 0.8 67 9 1952,1979 2017 2020 2017 top-third 2022 36 45.6 45.6 0.0 58 16 1979 2000 2020 2019 top-third 2019 48 45.4 45.6 -0.2 51 21 1968 2001,2002 2016 2020 top-third 2015 60 45.9 45.6 0.3 56 14 1969 2002 2018 2020 top-third 2000