1991-2020 Degrees Fahrenheit 1 61.0 56.4 4.6 91 3 1958 2017 1973 1974 top-tenth 2 54.3 52.4 1.9 84 10 1958 2017 1973 1938 top-third 3 50.7 49.6 1.1 77 15 1958 2017 1973 1972 top-third 2018 4 49.4 48.4 1.0 79 13 1964 2017 1973 1972 top-third 1952 5 50.8 49.2 1.6 87 5 1958 2017 1973 1950 top-tenth 2018 6 53.2 51.8 1.4 87 5 1958 2017 1973 1935 top-tenth 1995,2022 7 56.0 55.1 0.9 79 13 1977 2017 1973 1935 top-third 8 58.9 58.3 0.6 76 16 1977 2017 1973 1952 top-third 1986 9 61.1 61.0 0.1 69 23 1977 2017 1973 1957 top-third 1954,1957 10 62.7 63.0 -0.3 63 29 1977 2017 1973 1957 top-third 1978,2009 11 63.4 64.0 -0.6 56 35 1977 1999 1973 1957 normal 12 62.9 64.0 -1.1 40 51 1977 2017 1973 1972 normal 1972,1992,2014 18 57.9 59.9 -2.0 13 77 1977 2017 1969 1973 bottom-third 1943 24 62.0 64.0 -2.0 13 76 1977 2000 1973 1973 bottom-third 1970,1973,1989 36 62.3 64.0 -1.7 17 70 1977 2018 1973 1972 bottom-third 1934,1959 48 62.3 63.9 -1.6 16 69 1961,1977 2020 1973 1972 bottom-third 1970,1972,1975 60 62.3 63.9 -1.6 14 69 1977 2020,2021 1973 1972 bottom-third 1940,1960,1971,1972,1975