1925-2000 Degrees Fahrenheit 1 28.4 23.3 5.1 89 11 1985 2016 1925 1926 top-third 1989 2 24.5 17.1 7.4 96 4 1972 2019 1925 1926 top-tenth 3 17.4 13.0 4.4 85 15 1972 2019 1925 1926 top-third 4 16.8 10.3 6.5 95 5 1971 2016 1925 1926 top-tenth 5 14.0 9.0 5.0 90 9 1971 2016 1926 1926 top-tenth 6 14.2 9.4 4.8 91 8 1972 2016 1926 1926 top-tenth 7 16.9 11.7 5.2 91 8 1971 2016 1926 1926 top-tenth 8 20.1 15.3 4.8 92 7 1971 2019 1926 1926 top-tenth 2014 9 23.5 19.1 4.4 92 7 1971 2019 1926 1926 top-tenth 10 26.4 22.5 3.9 92 7 1971 2019 1926 1926 top-tenth 11 28.4 24.9 3.5 90 9 1971 2019 1926 1926 top-tenth 12 29.2 26.0 3.2 91 8 1971 2016 1926 1926 top-tenth 18 -99 20.4 -99 -99 -99 1972 2016 normal 24 -99 26.0 -99 -99 -99 1972 2019 normal 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