1991-2020 Degrees Fahrenheit 1 49.0 51.5 -2.5 24 106 2011 1934 1899 1900 bottom-third 2 47.0 48.5 -1.5 41 89 1955 1934 1899 1900 bottom-third 1904 3 43.7 45.4 -1.7 38 92 1929 1934 1899 1900 bottom-third 1971,1996,2014 4 41.1 43.1 -2.0 46 84 1929 1934 1899 1900 normal 1910,2009 5 40.7 41.5 -0.8 69 57 1929 1992 1899 1900 normal 6 40.3 41.5 -1.2 52 74 1929,1937 1992 1899 1900 normal 1904,1931,1945,1989 7 41.7 43.1 -1.4 42 82 1929 2016 1901 1900 normal 1943,1975,2008,2009 8 -99 45.9 -99 -99 -99 1917 2015,2016 normal 9 -99 49.2 -99 -99 -99 1913 2016 normal 10 -99 51.8 -99 -99 -99 1913,1917 2015 normal 11 -99 53.2 -99 -99 -99 1917 2016 normal 12 -99 53.7 -99 -99 -99 1917 2016 normal 18 -99 49.7 -99 -99 -99 1917 2016 normal 24 -99 53.8 -99 -99 -99 1917 2016 normal 36 -99 53.8 -99 -99 -99 1957 2016 normal 48 -99 53.8 -99 -99 -99 1913 2016 normal 60 -99 53.8 -99 -99 -99 1917 2016,2017,2018,2019 normal