1991-2020 Degrees Fahrenheit 1 45.1 47.3 -2.2 28 65 2018 1955 1966 1971 bottom-third 2 38.5 41.0 -2.5 36 57 1951,1960 2012 1970 1971 normal 3 30.1 34.7 -4.6 19 74 1936 2012 1969 1971 bottom-third 4 24.9 30.5 -5.6 11 82 1936 2012 1970 1971 bottom-third 1969 5 23.7 28.9 -5.2 12 80 1936 2012 1970 1971 bottom-third 1970 6 25.3 29.8 -4.5 14 78 1936 2012 1969 1971 bottom-third 7 29.2 32.7 -3.5 19 73 1936 2012 1970 1971 bottom-third 1952,1986 8 33.2 36.6 -3.4 19 72 1936 2012 1970 1971 bottom-third 9 37.6 40.5 -2.9 20 71 1936 2012 1970 1971 bottom-third 1975 10 40.8 43.9 -3.1 14 77 1936 2012 1970 1971 bottom-third 1970 11 43.6 46.2 -2.6 17 74 1936 2012 1970 1971 bottom-third 1947,1966 12 44.7 47.3 -2.6 15 76 1936 2012 1970 1971 bottom-third 1956,1978 18 38.7 41.5 -2.8 11 79 1979 2017 1970 1971 bottom-third 24 45.2 47.3 -2.1 15 74 1937,1952,1994 2017 1971 1969 bottom-third 1980 36 44.8 47.3 -2.5 5 82 1952 2017 1971 1970 bottom-tenth 1951,1979 48 44.7 47.4 -2.7 2 83 1952 2002,2005,2006,2007,2018 1953 1971 bottom-tenth 1953 60 45.0 47.4 -2.4 5 78 1952,1997 2006 1953 1971 bottom-tenth 1973