1991-2020 Degrees Fahrenheit 1 42.3 43.3 -1.0 34 41 1960 2012 2005 2008 normal 2 39.4 39.5 -0.1 47 28 1978 2012 2007 2008 normal 2010 3 35.8 37.5 -1.7 32 43 1978 2023 2005 2008 normal 2005 4 36.5 37.6 -1.1 38 36 1978 2012 2005 2008 normal 1989 5 38.2 39.5 -1.3 34 39 1978 2012 2003 2008 normal 1993 6 41.1 42.4 -1.3 34 39 1978 2002,2012 2003 2008 normal 7 45.2 46.2 -1.0 34 39 1977 2016 2004 2008 normal 2004 8 48.7 49.9 -1.2 32 41 1977 2016 2003 2008 normal 2011 9 52.0 53.0 -1.0 35 38 1977 2012 2005 2008 normal 2010 10 54.3 54.9 -0.6 42 31 1977 2012 2005 2008 normal 1960,1997 11 54.8 55.7 -0.9 38 35 1977 2012 2004 2008 normal 2010 12 54.8 55.5 -0.7 41 32 1968 2012,2020 2004 2008 normal 1990,1997 18 51.2 51.1 0.1 50 19 1978 2017,2023 2005 2008 top-third 1991 24 55.5 55.5 0.0 52 17 1978 2017 2005 2008 top-third 1954 36 55.7 55.4 0.3 53 12 1979 2022 2006 2008 top-third 2002 48 55.9 55.4 0.5 54 7 1970,1980 2023 2008 2008 top-third 2002,2008 60 55.7 55.3 0.4 51 7 1970 2020,2023 2008 2002 top-third 2002,2018