1991-2020 Degrees Fahrenheit 1 32.7 38.3 -5.6 9 80 1984 2012 1937 1936 bottom-tenth 2 32.2 35.1 -2.9 30 59 2015 2012 1936 1937 normal 3 33.3 33.4 -0.1 64 25 2015 2012 1936 1937 top-third 1989 4 33.5 34.0 -0.5 62 26 1948,1959 2012 1937 1937 top-third 1954,1974 5 34.3 36.2 -1.9 44 44 1948 2012 1937 1937 normal 1966 6 37.4 39.3 -1.9 41 47 1940 2012 1937 1937 normal 1955,1973,1996 7 40.9 43.0 -2.1 35 53 1940,1941 2012 1937 1937 normal 1955,1980 8 44.5 46.7 -2.2 32 56 1941 2012 1937 1937 normal 9 47.2 49.8 -2.6 23 65 1941 2012 1937 1937 bottom-third 1994 10 49.0 51.6 -2.6 23 65 1941 2012 1937 1937 bottom-third 11 50.0 52.2 -2.2 28 60 1941 2012 1937 1937 bottom-third 1964 12 49.5 51.9 -2.4 20 68 1941 2012 1937 1937 bottom-third 1962,1970,1975 18 -99 47.6 -99 -99 -99 1941 2023 normal 24 -99 51.8 -99 -99 -99 1941 2023 normal 36 -99 51.8 -99 -99 -99 1941 2023 normal 48 -99 51.8 -99 -99 -99 1941 2023 normal 60 -99 51.7 -99 -99 -99 1941 2023 normal