1991-2020 Degrees Fahrenheit 1 41.8 45.4 -3.6 20 65 1960 2012 1996 2012 bottom-third 2 38.9 41.6 -2.7 26 59 2015 2012 2007 2012 bottom-third 3 38.6 39.5 -0.9 46 39 1940 2012 2009 2012 normal 1972,1992,2005 4 39.9 39.6 0.3 61 24 1978 2012 2011 2012 top-third 1950,1952,1972,1974,1983 5 40.7 41.2 -0.5 50 34 1940 2012 2011 2012 normal 2019 6 43.8 44.1 -0.3 53 31 1977 2012 2011 2012 normal 7 47.7 47.8 -0.1 60 24 1977 2012 2011 2012 top-third 1953,1985,1990 8 51.5 51.5 0.0 61 23 1977 2012 2011 2012 top-third 9 55.0 54.6 0.4 68 16 1977 2012 2011 2012 top-third 1949,1974,1995,1999 10 56.9 56.6 0.3 64 19 1977 2012 2010 2012 top-third 1950 11 58.1 57.4 0.7 72 11 1977 2012 2011 2012 top-third 1991,2006,2011 12 58.0 57.3 0.7 73 10 1941,1977 2012 2010 2012 top-third 2006 18 54.8 52.9 1.9 80 2 1941 2017 2012 2013 top-tenth 24 59.2 57.2 2.0 80 1 1978 2012,2013 2012 2012 highest 2012 36 58.8 57.2 1.6 78 1 1979 2013 2012 2013 highest 48 58.2 57.2 1.0 72 5 1980 2023 2012 2013 top-tenth 2021 60 57.9 57.1 0.8 70 5 1966,1967,1968,1981 2020 2012 2012 top-tenth 2012