1991-2020 Degrees Fahrenheit 1 56.2 60.0 -3.8 13 67 1967 1992 1953 1950 bottom-third 2 54.6 59.1 -4.5 7 73 1975 2015 1953 1953 bottom-tenth 1953 3 55.9 58.3 -2.4 27 53 1949 2015 1953 1947 normal 1983 4 54.8 58.0 -3.2 19 61 1949 2015 1952 1953 bottom-third 5 54.7 57.7 -3.0 17 63 1949 2015 1952 1953 bottom-third 1965,1972 6 55.5 58.2 -2.7 25 55 1949 2015 1953 1954 bottom-third 7 56.5 59.4 -2.9 18 62 1949 2015 1953 1954 bottom-third 1971,1974 8 57.4 60.6 -3.2 12 68 1949 2015 1953 1947 bottom-third 1947,1969 9 58.2 61.5 -3.3 10 70 1949 2016 1953 1947 bottom-third 1946 10 59.2 62.2 -3.0 10 69 1949 2015 1953 1947 bottom-third 1969 11 59.4 62.5 -3.1 9 70 1949 2015 1953 1947 bottom-third 1955 12 59.4 62.5 -3.1 11 68 1949 2015 1953 1947 bottom-third 18 58.0 61.0 -3.0 10 69 1949 2015 1953 1954 bottom-third 1955 24 59.2 62.4 -3.2 7 71 1950 2016 1953 1948 bottom-tenth 36 59.0 62.4 -3.4 6 71 1951 2016 1953 1948 bottom-tenth 48 59.0 62.3 -3.3 6 70 1952 2017,2018 1953 1954 bottom-tenth 1956 60 58.9 62.3 -3.4 5 70 1952,1953 2018 1953 1954 bottom-tenth