1991-2020 Degrees Fahrenheit 1 42.2 45.1 -2.9 30 78 2018 1915 1972 1971 bottom-third 2 40.7 38.2 2.5 88 20 1965 2012 1972 1968 top-third 1915 3 33.8 31.7 2.1 84 24 1965,2014 2012 1972 1954 top-third 4 29.3 27.4 1.9 90 17 1979 2012 1972 1946 top-third 1915 5 25.6 26.0 -0.4 64 43 1979 2012 1972 1968 normal 6 26.5 27.2 -0.7 62 45 1979 2012 1972 1968 normal 1961 7 28.9 30.2 -1.3 47 60 1979 2012 1972 1968 normal 1913,1916,1933 8 32.5 34.0 -1.5 39 67 1979 2012 1972 1968 normal 1933,1944,2018 9 36.5 37.8 -1.3 41 64 1979 2012 1972 1968 normal 1913,1947 10 39.6 41.1 -1.5 33 72 1979 2012 1972 1968 bottom-third 1937,1960,1984,2018 11 41.9 43.4 -1.5 29 76 1979 2012 1971 1972 bottom-third 1937,1971 12 43.4 44.6 -1.2 35 70 1979 2012 1972 1964 bottom-third 2018 18 36.8 38.8 -2.0 21 83 1918 2017 1972 1969 bottom-third 1962,1975 24 43.3 44.6 -1.3 30 72 1918 2017 1972 1965 bottom-third 1985,1993,1995,1998,2014 36 43.2 44.6 -1.4 24 75 1918 2017 1972 1966 bottom-third 1917 48 42.9 44.6 -1.7 13 84 1980 1934 1972 1969 bottom-third 1962,1969 60 42.8 44.6 -1.8 8 87 1997 1935 1972 1968 bottom-tenth