1991-2020 Degrees Fahrenheit 1 48.1 50.1 -2.0 31 54 1950 2010 1961 1960 normal 2 41.0 44.2 -3.2 21 64 1984 2012 1960 1961 bottom-third 3 35.8 39.0 -3.2 22 63 1978 2012 1960 1961 bottom-third 1989 4 31.9 35.6 -3.7 13 72 1978 2012 1947 1961 bottom-third 1971 5 30.5 34.6 -4.1 11 74 1978 2012 1943 1961 bottom-third 1965 6 32.0 35.7 -3.7 13 71 1978 2012 1951 1961 bottom-third 7 35.1 38.2 -3.1 14 69 1978 2012 1951 1961 bottom-third 1943,1980 8 39.3 41.5 -2.2 21 62 1978 2017 1959 1961 bottom-third 1956 9 42.8 44.8 -2.0 22 61 1978 2017 1959 1961 bottom-third 10 45.9 47.7 -1.8 21 61 1978 2012 1959 1961 bottom-third 1958 11 47.9 49.8 -1.9 19 63 1978 2012 1959 1961 bottom-third 12 48.5 50.7 -2.2 15 67 1977 2012 1959 1961 bottom-third 18 43.6 45.7 -2.1 16 65 1979 2017 1959 1961 bottom-third 1965 24 48.8 50.7 -1.9 15 65 1978 2017 1959 1961 bottom-third 36 49.1 50.7 -1.6 19 59 1979 2018 1961 1958 bottom-third 1953,1967,1995 48 48.8 50.6 -1.8 10 66 1980 2019,2023 1962 1961 bottom-third 1963 60 48.9 50.6 -1.7 11 63 1981,1982 2020 1962 1961 bottom-third 1964,1967,1968,1969,1972,1983