1991-2020 Degrees Fahrenheit 1 41.9 50.3 -8.4 3 92 1960 2012 1941 1940 bottom-tenth 2 38.8 46.6 -7.8 6 89 1960 2012 1934 1940 bottom-tenth 3 38.4 44.3 -5.9 5 89 1978 2012 1940 1939 bottom-tenth 4 39.7 43.8 -4.1 12 82 1978 2012 1940 1939 bottom-third 5 41.4 45.0 -3.6 14 80 1940 2012 1940 1939 bottom-third 6 44.2 47.5 -3.3 12 81 1977 2017 1940 1939 bottom-third 1981 7 47.7 50.9 -3.2 13 80 1977 2017 1940 1939 bottom-third 8 51.2 54.2 -3.0 13 80 1977 2017 1940 1939 bottom-third 1960 9 54.0 56.9 -2.9 12 81 1977 2017 1940 1939 bottom-third 10 56.1 58.8 -2.7 11 82 1977 2017 1936 1940 bottom-third 11 57.0 59.6 -2.6 10 83 1977 2017 1936 1940 bottom-third 12 56.9 59.6 -2.7 6 87 1977 2017 1936 1940 bottom-tenth 18 52.2 55.5 -3.3 2 89 1978 2017 1941 1940 bottom-tenth 24 57.0 59.5 -2.5 6 85 1978 2017 1941 1940 bottom-tenth 1963,1977 36 57.7 59.5 -1.8 20 69 1970,1979 2018 1938 1940 bottom-third 1938,1961,1983 48 57.8 59.5 -1.7 20 67 1970 2019,2020 1941 1940 bottom-third 1960,1972,1977,1986 60 57.9 59.5 -1.6 25 60 1970 2020 1940 1940 bottom-third 1940