1991-2020 Degrees Fahrenheit 1 47.0 49.4 -2.4 21 64 1983 2021 1972 1971 bottom-third 2 54.3 53.0 1.3 69 16 1983,2000 2021 1972 1971 top-third 1956,1964,1999 3 59.0 57.7 1.3 71 14 1976 2021 1972 1971 top-third 2003 4 63.0 62.8 0.2 61 24 1976 2021 1972 1971 top-third 1941 5 66.1 67.1 -1.0 36 49 1976 2021 1972 1971 normal 6 68.6 69.8 -1.2 29 56 1976 2015 1972 1971 normal 1944,1953,1957,1982 7 69.9 71.4 -1.5 21 63 1976 2015 1972 1971 bottom-third 1958,1996,2000 8 70.0 71.7 -1.7 16 68 1976 2015 1972 1971 bottom-third 9 69.1 71.1 -2.0 13 71 1976 2015 1972 1971 bottom-third 1993 10 68.2 69.8 -1.6 19 65 1976,1983 2011,2016 1972 1971 bottom-third 1974 11 66.4 68.2 -1.8 15 69 1983 2016 1968 1972 bottom-third 1997 12 64.5 66.5 -2.0 14 70 1940 2016 1968 1972 bottom-third 18 65.4 67.6 -2.2 5 79 1968,1983 2016 1968 1972 bottom-tenth 1960,1976,1977,1979 24 64.8 66.5 -1.7 15 68 1979 2017 1969 1972 bottom-third 1962,1967,1974,1977 36 65.1 66.5 -1.4 23 59 1983 2017 1970 1972 bottom-third 1963,1967,1982 48 65.0 66.4 -1.4 22 59 1961 2018 1971 1972 bottom-third 1989 60 65.1 66.4 -1.3 24 56 1983 2019,2020 1972 1967 bottom-third 1960,1974,1975