1991-2020 Degrees Fahrenheit 1 72.9 73.9 -1.0 43 33 1976 2020 2014 2013 normal 2 71.7 71.9 -0.2 53 22 1972 1991 2014 2012 top-third 3 69.9 68.4 1.5 67 8 1961 1991 2014 2012 top-third 4 65.4 64.0 1.4 68 7 1961 1991 2014 2012 top-tenth 5 59.4 59.0 0.4 60 15 1950 2012 2014 2012 top-third 6 52.2 54.2 -2.0 27 48 1978 2012 2014 2013 normal 1992 7 48.2 50.5 -2.3 24 51 1978 2012 2014 2013 bottom-third 1969,1985 8 46.6 48.3 -1.7 30 45 1978 2012 2014 2013 normal 9 45.7 47.7 -2.0 31 43 1978 2012 2014 2013 normal 10 46.5 48.3 -1.8 29 45 1978 2012 2014 2013 normal 1952 11 48.1 49.9 -1.8 28 46 1978 2012 2014 2013 normal 1957,1962,1969 12 50.1 51.7 -1.6 31 43 1978 2012 2014 2013 normal 1969,2003 18 50.7 52.5 -1.8 27 46 1979 2012,2017 2014 2014 normal 1975,1984,1993,1997,2014 24 49.8 51.6 -1.8 28 44 1978 2017 1997 2014 normal 36 50.3 51.6 -1.3 36 34 1979 2018 1997 2014 normal 1986,1997 48 51.4 51.5 -0.1 52 16 1980 2019 2006 2014 top-third 2005 60 51.5 51.5 0.0 52 14 1981 2020 2011 2014 top-third 2009,2011