1991-2020 Degrees Fahrenheit 1 56.9 58.7 -1.8 37 42 1948 2015 1975 1972 normal 2 56.7 58.1 -1.4 36 43 1949 2015 1975 1972 normal 2009 3 57.3 57.9 -0.6 50 29 1949 2015 1975 1970 normal 2008 4 57.0 57.6 -0.6 49 30 1949 2015 1975 1970 normal 1998,2007 5 57.4 58.5 -1.1 37 42 1949 2015 1975 1970 normal 2002 6 58.5 59.8 -1.3 36 43 1949 2015 1975 1970 normal 7 60.0 61.2 -1.2 36 43 1949 2015 1975 1970 normal 8 60.8 62.3 -1.5 31 48 1949 2015 1975 1970 normal 9 61.6 63.0 -1.4 31 47 1949 2015 1975 1970 normal 10 61.7 63.3 -1.6 26 52 1949 2015 1975 1973 bottom-third 1973 11 61.5 63.3 -1.8 23 55 1949 2015 1975 1973 bottom-third 1979 12 61.0 63.1 -2.1 20 58 1949 2015 1974 1975 bottom-third 1957 18 59.8 62.0 -2.2 19 59 1949 2015 1975 1975 bottom-third 1975 24 61.1 63.0 -1.9 18 59 1950 2016 1975 1974 bottom-third 1958,1967 36 60.9 63.0 -2.1 14 62 1951 2016 1967 1975 bottom-third 48 61.1 62.9 -1.8 16 59 1952 2018 1975 1975 bottom-third 1959,1972,1975 60 61.1 62.9 -1.8 16 58 1952,1953 2018 1975 1974 bottom-third