1991-2020 Degrees Fahrenheit 1 63.3 63.1 0.2 38 22 1993 2015 1976 1973 normal 2 65.8 66.9 -1.1 20 40 1992 2021 1976 1973 bottom-third 1985,1999 3 68.6 68.8 -0.2 32 28 1992 2016 1976 1973 normal 1971,2013 4 67.7 68.7 -1.0 22 38 1992 2005 1975 1976 normal 1969,1980,1981,2014 5 67.4 66.7 0.7 45 15 1992 2018 1976 1977 top-third 6 64.9 63.5 1.4 53 7 1992 2010 1976 1977 top-third 2016 7 61.4 59.5 1.9 56 4 1992 2012 1976 1977 top-tenth 1991,2016 8 56.6 55.3 1.3 52 8 1965,1989 2012 1976 1977 top-third 1999 9 51.8 51.9 -0.1 39 21 1978,2014 2012 1975 1976 normal 1995 10 48.6 49.7 -1.1 26 34 2014 2012 1974 1976 normal 11 47.0 48.8 -1.8 13 46 1996,2014 2012 1972 1976 bottom-third 1971,1972,1992 12 47.0 49.0 -2.0 12 47 1979 2012 1970 1976 bottom-third 18 52.2 53.8 -1.6 12 47 1993 2012 1970 1976 bottom-third 1966 24 48.3 49.0 -0.7 28 30 1979 2017 1975 1976 normal 36 48.2 49.0 -0.8 22 35 1979 2012 1973 1976 normal 1973,2005 48 48.1 48.9 -0.8 18 38 1980,1981 2013 1974 1976 bottom-third 1974,1985 60 48.3 48.9 -0.6 23 32 1982 2020 1975 1976 normal 1992,1995