1991-2020 Degrees Fahrenheit 1 40.6 45.1 -4.5 16 91 2018 1915 1909 1917 bottom-third 2 38.3 38.3 0.0 68 39 1950 2012 1917 1915 normal 3 30.3 31.8 -1.5 58 49 1936 2012 1917 1915 normal 4 22.8 27.5 -4.7 20 86 1979 2012 1917 1916 bottom-third 5 19.9 26.1 -6.2 12 94 1979 2012 1917 1916 bottom-third 1982 6 22.5 27.4 -4.9 15 91 1979 2012 1917 1916 bottom-third 7 24.5 30.3 -5.8 9 97 1979 2012 1917 1916 bottom-tenth 8 28.6 34.2 -5.6 5 100 1979 2012 1917 1916 bottom-tenth 1951 9 32.7 37.9 -5.2 4 100 1979 2012 1918 1917 bottom-tenth 10 36.5 41.2 -4.7 3 101 1979 2012 1918 1917 bottom-tenth 11 38.7 43.6 -4.9 2 102 1979 2012 1918 1917 bottom-tenth 12 39.8 44.7 -4.9 1 103 1918 2012 1918 1917 lowest 18 33.2 38.9 -5.7 1 102 1918 2017 1918 1917 lowest 24 40.3 44.7 -4.4 1 100 1918 2017 1918 1917 lowest 36 40.7 44.7 -4.0 1 97 1918 2013,2017 1918 1917 lowest 48 41.7 44.7 -3.0 1 95 1918,1919 2013 1918 1917 lowest 1919 60 42.3 44.7 -2.4 2 92 1920 2002,2006,2016 1918 1917 bottom-tenth