1991-2020 Degrees Fahrenheit 1 34.6 32.5 2.1 59 18 1977 2023 1951 1950 top-third 2 34.4 34.9 -0.5 47 29 1961 2002 1951 1950 normal 3 35.8 38.7 -2.9 27 49 1977 2002,2016 1951 1951 normal 1951,1990 4 41.1 43.3 -2.2 31 45 1977 2002 1951 1950 normal 1955,1969,1973,1990,2009 5 46.2 48.6 -2.4 27 48 1977 2016 1951 1950 normal 2014 6 50.8 53.2 -2.4 26 49 1977 2016 1951 1950 normal 1955,1966,2014 7 54.3 56.7 -2.4 22 53 1977 2017 1951 1950 bottom-third 1955,1978,1984,1988,1990 8 56.4 58.8 -2.4 24 51 1977 2017 1951 1950 bottom-third 9 57.1 59.4 -2.3 19 56 1977 2016 1951 1950 bottom-third 1975,1987,1990 10 56.6 58.9 -2.3 22 53 1977 2016 1951 1950 bottom-third 1982 11 55.2 57.5 -2.3 19 56 1977 2017 1951 1950 bottom-third 1962,1967,1982,1985,1990 12 53.4 55.6 -2.2 22 53 1968 2013 1951 1950 bottom-third 1940,1962,1987,1990 18 52.3 54.7 -2.4 15 58 1941,1964,1968 2017 1951 1950 bottom-third 1961,1971,1977,1982 24 52.6 55.5 -2.9 3 70 1964,1968 2013 1941 1951 bottom-tenth 1941,1969 36 53.5 55.5 -2.0 21 50 1963,1965 2023 1946 1951 bottom-third 1946,1962,1971 48 53.7 55.5 -1.8 29 40 1964 2023 1951 1950 normal 1972,1976,1977 60 53.4 55.5 -2.1 19 48 1965,1968 2023 1945 1951 bottom-third 1959,1983