1991-2020 Degrees Fahrenheit 1 45.5 52.7 -7.2 2 91 1947 1982 1947 1955 bottom-tenth 2 40.7 46.3 -5.6 3 90 1947 2010 1950 1955 bottom-tenth 3 34.2 40.0 -5.8 3 90 1950 2010 1950 1955 bottom-tenth 4 30.5 34.6 -4.1 12 81 1934 2010 1950 1955 bottom-third 5 27.9 31.0 -3.1 22 71 1934 2012 1950 1955 bottom-third 1974 6 26.3 29.9 -3.6 16 75 2014 2012 1950 1955 bottom-third 2015 7 27.0 30.7 -3.7 11 80 1934 2012 1950 1955 bottom-third 8 29.7 32.7 -3.0 14 77 1934 2012 1950 1955 bottom-third 1977 9 32.6 35.6 -3.0 13 78 1934 2012 1950 1955 bottom-third 1977,1979 10 36.3 38.7 -2.4 22 69 1934 2012 1950 1955 bottom-third 1957 11 39.5 41.2 -1.7 33 58 1934 2012 1952 1955 normal 1945,1961,1972 12 41.5 42.9 -1.4 40 51 1934 2012 1952 1955 normal 1974 18 37.6 38.5 -0.9 57 32 2015 1999 1955 1949 normal 2005 24 41.7 42.8 -1.1 49 40 1935 2017 1952 1955 normal 1973,1975,1996 36 41.9 42.8 -0.9 53 34 1936 2000 1952 1956 normal 48 -99 42.9 -99 -99 -99 1937 2013 normal 60 -99 42.8 -99 -99 -99 1938 2002 normal