1991-2020 Degrees Fahrenheit 1 15.0 19.9 -4.9 27 49 2019 1954 1956 1957 normal 2 19.3 18.3 1.0 50 26 1950 1992 1957 1953 normal 1974 3 21.6 19.0 2.6 57 18 1950 1992 1957 1953 top-third 2020 4 23.6 21.9 1.7 56 19 1979 2000 1957 1954 top-third 5 27.4 26.4 1.0 52 23 1979 2000 1957 1954 top-third 1975 6 32.0 31.8 0.2 47 28 1952 1998 1957 1954 normal 2015 7 37.1 37.1 0.0 46 29 1978 1998 1957 1954 normal 8 41.7 41.2 0.5 47 28 1952 1999 1957 1954 normal 9 43.8 43.6 0.2 44 30 1952 1998 1957 1954 normal 10 44.8 44.5 0.3 45 29 1952 1998 1957 1954 normal 11 44.2 44.3 -0.1 45 29 1952 1981,1999 1957 1954 normal 2017 12 42.8 43.2 -0.4 43 31 1952 2016 1957 1954 normal 18 38.2 39.4 -1.2 28 45 1952 2000 1957 1955 normal 1965 24 42.0 43.2 -1.2 28 44 1952 2000 1957 1955 normal 36 41.4 43.2 -1.8 16 54 1952 2000 1957 1956 bottom-third 1966,1969 48 41.4 43.3 -1.9 13 55 1953 1992,2002 1957 1957 bottom-third 1957,1970,1979 60 41.7 43.4 -1.7 18 48 1954 2002 1956 1957 bottom-third 1967,1976