1991-2020 Degrees Fahrenheit 1 60.6 60.3 0.3 46 23 1956 2015 1976 1970 top-third 2 57.3 58.6 -1.3 27 40 1955 2015 1975 1976 normal 1965,1969,1982 3 56.2 57.5 -1.3 23 40 1966 2015 1975 1976 normal 4 57.9 59.1 -1.2 24 39 1973 1996 1975 1976 normal 1989,1998,2011 5 61.0 62.7 -1.7 17 45 1973 2015 1975 1976 bottom-third 1958 6 64.5 67.0 -2.5 9 53 1973 1996,2015 1975 1976 bottom-third 1960,1971,1975 7 68.1 70.9 -2.8 4 58 1973 1996 1973 1976 bottom-tenth 8 70.9 73.8 -2.9 3 59 1973 1996 1973 1976 bottom-tenth 9 72.6 75.4 -2.8 4 58 1973 2015 1973 1976 bottom-tenth 10 73.3 75.9 -2.6 5 57 1972 2015 1973 1976 bottom-tenth 11 72.8 75.6 -2.8 5 57 1972 2015,2018 1976 1975 bottom-tenth 12 71.9 74.8 -2.9 4 58 1972 2018 1976 1975 bottom-tenth 18 69.7 72.3 -2.6 6 51 1974 2016,2018 1976 1975 bottom-tenth 24 71.8 74.9 -3.1 1 56 1973,1977 2018 1973 1976 lowest 1973 36 72.1 74.9 -2.8 3 49 1974 2018 1974 1976 bottom-tenth 48 72.1 74.9 -2.8 2 45 1974 2018 1975 1976 bottom-tenth 1975 60 72.1 74.8 -2.7 2 40 1976 2018 1976 1975 bottom-tenth