1991-2020 Degrees Fahrenheit 1 49.7 55.4 -5.7 4 72 1967 2015 1956 1965 bottom-tenth 2 44.6 49.2 -4.6 3 73 1967 2010 1956 1965 bottom-tenth 3 39.7 42.8 -3.1 9 67 1967 2012 1956 1965 bottom-third 1969 4 34.5 37.4 -2.9 11 64 1967 2012 1963 1965 bottom-third 2003,2007 5 30.7 33.7 -3.0 11 63 1971 2012 1965 1965 bottom-third 1956,1965,1968 6 29.8 32.4 -2.6 19 54 1971 2012 1965 1964 bottom-third 2001 7 30.1 32.9 -2.8 16 57 1971 2012 1963 1965 bottom-third 8 32.1 34.8 -2.7 14 59 1971 2012 1965 1965 bottom-third 1965,1977,1981 9 34.9 37.5 -2.6 15 58 1971 2012 1965 1964 bottom-third 1981,1982 10 37.9 40.5 -2.6 14 59 1971 2012 1965 1964 bottom-third 1961,1969 11 40.2 43.0 -2.8 8 64 1963 2012 1965 1964 bottom-third 1994 12 41.9 44.8 -2.9 5 66 1963 2012 1965 1965 bottom-tenth 1965,1967 18 37.8 40.8 -3.0 6 61 1971 2017 1963 1965 bottom-tenth 1967 24 41.9 45.0 -3.1 1 64 1966,1967,1971,1978 2013 1966 1965 lowest 1967,1971,1978 36 42.4 45.1 -2.7 7 53 1967 2023 1965 1964 bottom-third 1970,1972,1973 48 42.1 45.1 -3.0 1 55 1966,1968 2013,2023 1966 1965 lowest 1968 60 42.5 45.1 -2.6 8 44 1967 2013,2023 1965 1965 bottom-third 1965