1991-2020 Degrees Fahrenheit 1 51.4 45.1 6.3 104 4 2018 1915 1954 1915 top-tenth 2 39.1 38.2 0.9 71 37 1965 2012 1954 1946 normal 1911 3 30.9 31.7 -0.8 62 46 1965,2014 2012 1953 1954 normal 1934 4 26.5 27.4 -0.9 57 50 1979 2012 1953 1954 normal 2009 5 25.5 26.0 -0.5 63 44 1979 2012 1953 1954 normal 1933 6 27.2 27.2 0.0 72 35 1979 2012 1953 1954 top-third 7 29.9 30.2 -0.3 68 39 1979 2012 1953 1954 normal 1980 8 33.6 34.0 -0.4 66 40 1979 2012 1953 1954 normal 1935,1949,1961,1992 9 37.3 37.8 -0.5 57 48 1979 2012 1953 1954 normal 10 40.9 41.1 -0.2 65 40 1979 2012 1953 1954 normal 1961 11 43.5 43.4 0.1 67 38 1979 2012 1953 1954 normal 1945,2020 12 44.2 44.6 -0.4 58 47 1979 2012 1953 1954 normal 1933,2010 18 39.1 38.8 0.3 79 25 1918 2017 1953 1954 top-third 24 45.1 44.6 0.5 82 20 1918 2017 1954 1942 top-third 2005 36 44.6 44.6 0.0 72 27 1918 2017 1954 1942 top-third 2021 48 44.1 44.6 -0.5 57 40 1980 1934 1954 1945 normal 1956,1989 60 43.5 44.6 -1.1 30 65 1997 1935 1954 1950 bottom-third 1947,1960,1978,1983