1991-2020 Degrees Fahrenheit 1 67.3 70.7 -3.4 21 93 1928 1956 1920 1922 bottom-third 2 61.0 65.1 -4.1 12 101 1915 1934 1917 1922 bottom-third 3 56.7 59.8 -3.1 16 96 1995 1934,2012 1920 1922 bottom-third 1997 4 51.1 55.3 -4.2 9 103 1915 2012 1920 1922 bottom-tenth 5 46.2 50.7 -4.5 4 107 1915 2012 1917 1922 bottom-tenth 6 44.1 47.3 -3.2 16 94 1915 2012 1922 1921 bottom-third 1942,1984 7 42.1 44.9 -2.8 19 90 1915 2012 1922 1921 bottom-third 1945 8 41.6 44.2 -2.6 18 91 1917 1934,2012 1922 1922 bottom-third 1897,1922,1944 9 42.9 45.1 -2.2 20 89 1917 1934,2012 1920 1922 bottom-third 10 45.4 47.1 -1.7 27 80 1917 1934 1917 1922 bottom-third 1936,1942,2019 11 48.1 49.5 -1.4 35 72 1917,1993 1934 1922 1921 bottom-third 1982,1988 12 50.2 51.7 -1.5 24 83 1993 2012 1917 1922 bottom-third 1925,1942,1983,2007,2019 18 48.1 50.3 -2.2 13 94 1916 2016 1918 1922 bottom-third 1945,1951,1952,1960,1983 24 50.2 51.7 -1.5 19 86 1917 2017 1918 1922 bottom-third 1951,1995,1998 36 50.5 51.7 -1.2 28 75 1917 2017,2018 1918 1923 bottom-third 1953,1971,1974,1979,1998 48 -99 51.7 -99 -99 -99 1918 2018 normal 60 -99 51.7 -99 -99 -99 1930 2006 normal