1925-2000 Degrees Fahrenheit 1 14.8 23.3 -8.5 2 98 1985 2016 1927 1926 bottom-tenth 2 9.4 17.1 -7.7 2 98 1972 2019 1927 1926 bottom-tenth 3 8.6 13.0 -4.4 8 92 1972 2019 1927 1926 bottom-tenth 4 7.8 10.3 -2.5 18 82 1971 2016 1925 1926 bottom-third 5 6.5 9.0 -2.5 15 84 1971 2016 1927 1926 bottom-third 1933,1952,1965 6 8.5 9.4 -0.9 30 69 1972 2016 1927 1926 bottom-third 1973 7 11.6 11.7 -0.1 39 60 1971 2016 1927 1926 normal 1967 8 15.7 15.3 0.4 43 56 1971 2019 1927 1926 normal 1992,2006 9 19.7 19.1 0.6 46 53 1971 2019 1927 1926 normal 1983,1986 10 23.1 22.5 0.6 53 46 1971 2019 1927 1926 normal 1937,1938,1950,1953,1968 11 25.8 24.9 0.9 56 43 1971 2019 1927 1926 normal 1996,2000 12 26.9 26.0 0.9 58 41 1971 2016 1927 1926 normal 1937,1963 18 22.6 20.4 2.2 76 22 1972 2016 1927 1927 top-third 24 28.0 26.0 2.0 84 14 1972 2019 1927 1927 top-third 1945,2001 36 -99 26.0 -99 -99 -99 1973 2016 normal 48 -99 25.9 -99 -99 -99 1974 2019 normal 60 -99 25.9 -99 -99 -99 1975 2019 normal