1901-2000 Degrees Fahrenheit 1 25.97 22.60 3.37 112 17 1909 2015 1964 1959 top-third 1959 2 29.90 26.64 3.26 123 6 1976 2015 1964 1965 top-tenth 3 33.67 31.56 2.11 119 10 1976 2015 1964 1941 top-tenth 4 37.81 36.65 1.16 101 28 1976 2015 1964 1941 top-third 1939 5 41.91 41.13 0.78 91 38 1976 2015 1964 1947 top-third 6 44.89 44.36 0.53 81 48 1976 2021 1964 1954 normal 1984 7 46.28 45.97 0.31 68 61 1976 2021 1964 1963 normal 2009 8 46.52 46.16 0.36 71 58 1976 2015 1964 1963 normal 9 45.82 45.32 0.50 90 39 1917 2015 1964 1957 top-third 1957 10 43.67 43.79 -0.12 51 78 1917 2015 1964 1963 normal 1901 11 41.59 41.88 -0.29 42 87 1917 2016 1964 1963 bottom-third 12 39.89 40.04 -0.15 57 72 1917 2016 1964 1961 normal 18 41.22 41.48 -0.26 42 86 1917 2016 1964 1963 bottom-third 24 39.66 40.03 -0.37 29 99 1917 2017 1964 1963 bottom-third 36 39.73 40.02 -0.29 37 90 1918 2017 1964 1963 bottom-third 1909,1944,1962 48 39.75 40.01 -0.26 31 95 1919 2018 1952 1964 bottom-third 1945 60 39.79 40.00 -0.21 35 90 1920 2019 1964 1963 bottom-third 1927