1991-2020 Degrees Fahrenheit 1 83.4 81.3 2.1 75 1 1950 2000 1999 2000 highest 2 81.0 80.4 0.6 64 12 1961 2022 1999 1998 top-third 3 79.3 78.1 1.2 67 9 1961 2022 1999 1998 top-third 4 75.5 75.2 0.3 62 14 1961 2022 1999 1998 top-third 1948 5 72.9 72.2 0.7 64 12 1983 2022 1999 2000 top-third 6 70.2 69.2 1.0 67 9 1958,1983 2018 1999 2000 top-third 7 67.7 66.5 1.2 68 8 1978 2012 1999 2000 top-tenth 8 65.6 64.8 0.8 64 11 1978 2017 1998 1999 top-third 2006 9 64.8 64.1 0.7 64 11 1978 2017 1998 1999 top-third 2009 10 65.1 64.5 0.6 64 11 1977 2017 1998 1999 top-third 11 66.0 65.6 0.4 65 10 1977 2017 1998 1999 top-third 1957,1991,2005,2011 12 67.5 66.9 0.6 65 10 1977 2017 1998 1999 top-third 2011 18 68.1 67.7 0.4 65 10 1984 2017 1998 1999 top-third 2013 24 67.8 66.9 0.9 68 6 1978 2017 1999 2000 top-tenth 2016,2021 36 67.2 66.8 0.4 65 8 1970,1978 2018,2019 1999 2000 top-third 2006,2012 48 66.9 66.8 0.1 59 13 1961,1971,1980 2019,2020 1999 2000 top-third 2002,2014 60 66.6 66.7 -0.1 51 20 1970 2020 1999 2000 top-third 2014