1991-2020 Degrees Fahrenheit 1 34.6 32.1 2.5 67 16 1943 2012 1980 1977 top-third 2 28.4 26.3 2.1 69 14 2014 2012 1980 1977 top-third 3 24.3 23.1 1.2 65 17 2014 2012 1980 1973 top-third 1946 4 22.8 23.0 -0.2 61 21 2014 2012 1980 1973 top-third 5 25.2 25.3 -0.1 58 22 2014 2012 1980 1973 top-third 1973,1992 6 28.2 29.2 -1.0 50 30 2014 2012 1980 1976 normal 1990 7 32.6 33.8 -1.2 52 28 1977,2014 2016 1980 1976 normal 1973 8 37.2 38.2 -1.0 53 27 1943,1951,1965,1977,2014 2016 1980 1976 normal 1945,1976,1985,2011,2018 9 41.1 41.9 -0.8 53 27 1951 2012 1980 1976 normal 1988 10 43.5 44.4 -0.9 48 32 1951 2012 1980 1976 normal 1945,1985,2003 11 45.0 45.6 -0.6 51 29 1943,1951 2012 1980 1976 normal 1945 12 45.2 45.6 -0.4 54 26 1951 2016 1980 1964 top-third 2005 18 39.0 40.1 -1.1 42 35 1952 2017 1980 1976 normal 1945 24 44.2 45.6 -1.4 34 43 1952 2017 1980 1974 normal 36 43.6 45.6 -2.0 16 59 1953 2000 1980 1978 bottom-third 1945,1973,1977 48 43.7 45.6 -1.9 19 54 1980 2002 1980 1978 bottom-third 1958,1967,1978,1994 60 43.5 45.6 -2.1 12 59 1969,1971,1972 2002 1980 1978 bottom-third 1967,1997