1991-2020 Degrees Fahrenheit 1 60.3 62.5 -2.2 29 50 1964 2014 1965 1967 normal 1982 2 59.6 61.3 -1.7 41 38 1967 2014 1967 1966 normal 1979 3 59.0 60.2 -1.2 40 39 1975 2014 1967 1966 normal 4 58.8 59.4 -0.6 52 27 1948 2014 1967 1968 normal 5 57.9 58.9 -1.0 44 35 1949 2014 1967 1959 normal 1959 6 57.1 58.5 -1.4 38 41 1949 2014 1967 1959 normal 1977,2002 7 57.8 58.9 -1.1 41 38 1949 2014 1967 1959 normal 8 58.9 59.8 -0.9 45 34 1949 2014 1967 1959 normal 9 60.1 60.8 -0.7 48 31 1949 2016 1967 1959 normal 1980,2005 10 61.2 61.6 -0.4 57 22 1949 2016 1967 1959 top-third 1978 11 61.8 62.2 -0.4 56 22 1949 2016 1967 1959 top-third 1959 12 61.7 62.5 -0.8 46 32 1949 2015,2016 1967 1960 normal 1960 18 59.7 61.1 -1.4 34 44 1949 2015 1967 1960 normal 1979,2002 24 61.0 62.4 -1.4 29 48 1950 2016 1967 1961 normal 1979 36 60.7 62.4 -1.7 24 52 1950,1951 2016 1967 1962 bottom-third 1962,1977 48 60.4 62.4 -2.0 19 56 1951 2017,2018 1967 1963 bottom-third 60 60.5 62.3 -1.8 19 55 1952 2018 1967 1964 bottom-third 1977