1991-2020 Degrees Fahrenheit 1 64.2 67.6 -3.4 19 77 1954 2018 1967 1966 bottom-third 2 61.0 63.5 -2.5 18 78 1961 2019 1966 1967 bottom-third 1951,2005 3 57.2 59.1 -1.9 35 61 1960 2012 1966 1967 normal 1935 4 51.4 55.1 -3.7 10 86 1960,1978 2012 1960 1967 bottom-tenth 5 47.8 51.9 -4.1 5 90 1978 2012,2017 1966 1967 bottom-tenth 1966 6 47.0 50.4 -3.4 12 83 1978 2012 1966 1967 bottom-third 1956 7 46.7 50.2 -3.5 8 87 1940 2012 1963 1967 bottom-tenth 1963 8 47.9 51.5 -3.6 8 86 1978 2017 1961 1967 bottom-tenth 9 49.7 53.7 -4.0 4 90 1978 2017 1931 1967 bottom-tenth 10 52.2 56.0 -3.8 2 92 1977 2017 1931 1967 bottom-tenth 1931 11 54.3 58.1 -3.8 2 92 1977 2017 1968 1967 bottom-tenth 12 55.7 59.5 -3.8 2 92 1977 2017 1968 1967 bottom-tenth 18 53.1 56.5 -3.4 1 92 1968 2017 1968 1967 lowest 24 56.4 59.5 -3.1 3 89 1978 2017 1968 1967 bottom-tenth 36 56.5 59.5 -3.0 1 89 1968,1969,1970 2018 1968 1967 lowest 1969,1970 48 56.9 59.5 -2.6 5 83 1969 2019 1964 1967 bottom-tenth 1964,1971 60 56.8 59.5 -2.7 2 84 1970 2020 1968 1967 bottom-tenth