1991-2020 Degrees Fahrenheit 1 68.9 73.9 -5.0 2 74 1976 2020 1976 1978 bottom-tenth 2 67.4 72.0 -4.6 2 73 1972 1991 1972 1978 bottom-tenth 3 63.7 68.4 -4.7 1 74 1979 1991 1979 1978 lowest 4 59.4 64.0 -4.6 4 71 1961 1991 1972 1978 bottom-tenth 5 55.8 59.0 -3.2 14 61 1950 1991,2012 1978 1977 bottom-third 6 49.2 54.2 -5.0 3 72 1978 2012 1978 1977 bottom-tenth 7 45.0 50.5 -5.5 2 73 1978 2012 1978 1977 bottom-tenth 8 43.4 48.3 -4.9 3 72 1978 2012 1978 1977 bottom-tenth 1961 9 43.3 47.7 -4.4 3 71 1978 2012 1978 1977 bottom-tenth 1961 10 43.9 48.3 -4.4 3 71 1978 2012 1978 1977 bottom-tenth 11 46.1 49.9 -3.8 4 70 1978 2012 1978 1976 bottom-tenth 12 48.2 51.8 -3.6 4 70 1963,1978 2012 1978 1976 bottom-tenth 1958,1970 18 48.3 52.6 -4.3 1 72 1979 2012 1979 1978 lowest 24 47.7 51.7 -4.0 2 70 1978 2017 1978 1977 bottom-tenth 36 47.6 51.6 -4.0 1 69 1979 2018 1979 1978 lowest 48 48.3 51.6 -3.3 2 66 1980 2019 1979 1978 bottom-tenth 60 48.6 51.5 -2.9 5 61 1981 2020 1967 1978 bottom-tenth