1991-2020 Degrees Fahrenheit 1 57.5 63.5 -6.0 3 73 1967 2018 1961 1960 bottom-tenth 2 52.6 58.5 -5.9 1 75 1961 1991 1961 1960 lowest 3 50.4 53.0 -2.6 12 64 1984 2012 1960 1959 bottom-third 4 47.2 47.9 -0.7 36 40 1978 2012 1960 1959 normal 1965 5 42.5 44.3 -1.8 20 56 1978 2012,2017 1960 1959 bottom-third 1956 6 39.7 42.7 -3.0 7 68 1978 2012 1961 1960 bottom-tenth 1977 7 40.5 42.9 -2.4 13 62 1978 2012 1956 1960 bottom-third 8 42.4 44.4 -2.0 17 58 1978 2012 1958 1960 bottom-third 9 45.3 47.0 -1.7 16 59 1978 2017 1959 1960 bottom-third 1959,2011 10 48.3 49.7 -1.4 18 57 1977 2017 1959 1960 bottom-third 1967,2001 11 50.5 52.1 -1.6 16 59 1977 2017 1959 1960 bottom-third 1959,2001 12 52.2 53.7 -1.5 17 58 1977 2017 1959 1960 bottom-third 18 48.5 50.1 -1.6 17 57 1978,1979 2017 1959 1960 bottom-third 24 52.7 53.7 -1.0 23 51 1978 2017 1960 1958 bottom-third 2010 36 52.4 53.7 -1.3 12 61 1979 2018 1960 1960 bottom-third 1960,1969,1971,1984 48 52.4 53.7 -1.3 13 59 1980 2019 1961 1960 bottom-third 1969 60 52.7 53.6 -0.9 20 51 1981 2020 1961 1960 bottom-third 1996