1991-2020 Degrees Fahrenheit 1 46.6 50.0 -3.4 16 60 1976 1985 1997 2001 bottom-third 2 54.1 55.7 -1.6 29 47 1976 2016 1997 2001 normal 1960,1961,1979,1992,2013 3 61.1 61.4 -0.3 49 27 1976 2016 2001 2001 normal 1965,1994,2001 4 65.9 65.9 0.0 52 24 1976 2016 2001 2000 top-third 2000 5 68.8 68.8 0.0 53 23 1976 2016 2001 2000 top-third 1978,2000 6 70.2 70.1 0.1 55 21 1976 2016 2001 1999 top-third 2017 7 69.6 70.0 -0.4 45 31 1976 2016 2001 2000 normal 1955,1990 8 68.6 68.8 -0.2 52 24 1976 2016 2001 2001 top-third 1948,2001 9 66.5 66.8 -0.3 49 27 1976 2016 2001 2000 normal 1986 10 64.0 64.4 -0.4 45 31 1960 2016 2001 2000 normal 11 62.0 62.1 -0.1 54 22 1979 2016 2001 2000 top-third 2015 12 60.6 60.5 0.1 56 18 1979 2016 2001 2000 top-third 1991 18 63.5 63.7 -0.2 53 21 1968,1977 2017 2001 2000 top-third 2010 24 59.7 60.6 -0.9 43 29 1979 2017 1997 2001 normal 1956,1986 36 60.1 60.6 -0.5 48 22 1980 2018 1998 2001 top-third 2005 48 60.4 60.6 -0.2 52 16 1979 2019 1999 2001 top-third 1955,2015 60 60.6 60.5 0.1 54 12 1980 2020 2001 2002 top-third 2011,2012,2013