1991-2020 Degrees Fahrenheit 1 46.5 49.9 -3.4 28 74 1943 2017 1975 1978 bottom-third 1988 2 44.0 44.3 -0.3 69 33 1940 2012 1978 1977 top-third 1995 3 35.1 39.7 -4.6 14 88 1934 2012 1978 1977 bottom-third 1972 4 32.6 36.8 -4.2 15 85 1940 2023 1978 1977 bottom-third 5 32.2 36.1 -3.9 18 82 1970,1978 2012 1978 1976 bottom-third 1956,1996 6 33.7 37.0 -3.3 20 78 1934 2012 1978 1976 bottom-third 1968,2003 7 36.1 39.3 -3.2 16 81 1934 2012 1978 1976 bottom-third 1935,1941,1956,2014 8 39.2 42.4 -3.2 16 81 1934 2012 1978 1976 bottom-third 1948 9 42.7 45.7 -3.0 17 80 1934 2012 1978 1976 bottom-third 10 45.3 48.4 -3.1 15 82 1926 2012 1978 1976 bottom-third 11 47.4 50.3 -2.9 15 82 1934 2012 1978 1976 bottom-third 1948,1959,1993 12 48.3 51.1 -2.8 18 79 1926 2012 1978 1976 bottom-third 18 42.8 46.4 -3.6 3 90 1941 2017 1978 1978 bottom-tenth 1935,1978 24 48.1 51.1 -3.0 5 88 1926 2017 1978 1977 bottom-tenth 1964 36 47.9 51.0 -3.1 1 88 1979 2021,2023 1979 1978 lowest 48 48.6 51.0 -2.4 8 78 1980 2023 1971 1978 bottom-tenth 1942,1944,1965,1968 60 48.6 50.9 -2.3 7 76 1965 2023 1972 1978 bottom-tenth 1967,1968,1972,1982