1991-2020 Degrees Fahrenheit 1 29.5 33.2 -3.7 26 58 1977 2023 1963 1964 bottom-third 2 33.6 35.8 -2.2 36 48 1977 2016 1964 1960 normal 1941 3 38.2 39.5 -1.3 40 43 1977 2016 1964 1960 normal 2018 4 41.9 44.0 -2.1 30 53 1977 2016 1963 1964 normal 1997 5 47.0 49.1 -2.1 26 57 1977 2016 1964 1962 bottom-third 1966,1987 6 51.3 53.6 -2.3 19 64 1977 2016 1964 1962 bottom-third 1984,1990,1994 7 54.9 57.2 -2.3 21 62 1977 2016 1964 1962 bottom-third 1951,1993 8 57.1 59.1 -2.0 21 61 1977 2016 1964 1962 bottom-third 1957,1969,1984,1988,1990 9 58.1 59.6 -1.5 30 52 1977 2016 1964 1960 normal 1955,1986 10 57.4 59.1 -1.7 31 51 1977 2016 1964 1960 normal 1989 11 56.1 57.6 -1.5 32 49 1977 2016 1964 1958 normal 1942,1989,1996 12 54.1 55.8 -1.7 35 46 1968 2013,2017 1964 1958 normal 18 52.9 55.0 -2.1 20 60 1945,1964,1978 2017 1964 1961 bottom-third 1957,1985,1994 24 53.5 55.7 -2.2 12 66 1969 2013 1964 1959 bottom-third 1978,1980,1981,1994 36 53.2 55.7 -2.5 7 68 1970 2022,2023 1964 1959 bottom-tenth 48 53.4 55.6 -2.2 9 63 1964,1970,1971 2023 1964 1959 bottom-third 60 53.2 55.6 -2.4 2 67 1970 2023 1965 1959 bottom-tenth 1968,1971