1991-2020 Degrees Fahrenheit 1 46.9 45.4 1.5 71 23 1983 2021 1953 1951 top-third 1940 2 50.1 49.3 0.8 72 22 1932 2021 1953 1949 top-third 1966,1996,2010 3 55.2 54.7 0.5 71 23 1932 2021 1953 1950 top-third 4 60.9 59.9 1.0 78 16 1932 2021 1953 1934 top-third 5 65.2 64.4 0.8 80 14 1976 2021 1953 1946 top-third 1946,1965,2007,2011,2017 6 68.2 67.5 0.7 77 17 1976 2021 1953 1951 top-third 1946,2017 7 69.9 69.5 0.4 75 19 1976 2021 1953 1951 top-third 1999,2014 8 69.8 70.1 -0.3 63 30 1976 1998 1952 1953 top-third 2000 9 69.6 69.6 0.0 67 26 1976 2022 1953 1951 top-third 2000 10 68.1 68.3 -0.2 68 25 1976 2011 1952 1953 top-third 1951,1956 11 66.7 66.6 0.1 76 17 1976 2011 1953 1946 top-third 1946 12 65.0 64.8 0.2 74 17 1976 2017 1953 1953 top-third 1953 18 65.6 65.6 0.0 74 17 1976 2017 1953 1934 top-third 2002 24 65.0 64.7 0.3 75 14 1976 2017 1953 1954 top-third 36 64.7 64.7 0.0 70 17 1976 2018 1953 1954 top-third 48 64.6 64.6 0.0 65 20 1976 2019,2020 1953 1954 top-third 60 64.6 64.6 0.0 65 18 1976 2020 1953 1954 top-third 1999,2005