1991-2020 Degrees Fahrenheit 1 63.4 64.6 -1.2 36 60 1953 2015 1928 1929 normal 2 60.1 61.3 -1.2 39 57 1953 2015 1929 1928 normal 1966 3 55.6 57.5 -1.9 19 77 2011 1992 1929 1928 bottom-third 1933,1948,1959 4 53.0 54.2 -1.2 37 59 1955 2015 1929 1928 normal 1974,2002,2019 5 47.5 51.0 -3.5 4 92 1955 2015 1929 1928 bottom-tenth 6 43.2 48.3 -5.1 3 93 1950 1934 1929 1928 bottom-tenth 7 41.5 46.2 -4.7 2 93 1950 1934 1929 1929 bottom-tenth 8 41.3 45.5 -4.2 3 92 1950 1934 1929 1929 bottom-tenth 9 42.4 46.2 -3.8 4 91 1950 1934 1929 1929 bottom-tenth 1937 10 44.0 47.9 -3.9 3 92 1950 2015 1929 1929 bottom-tenth 1949 11 46.1 50.1 -4.0 2 93 1950 2015 1929 1929 bottom-tenth 1949 12 48.4 52.0 -3.6 4 91 1950 2015 1929 1929 bottom-tenth 18 47.7 50.8 -3.1 6 89 1930,1950 2016 1929 1929 bottom-tenth 1937,1951 24 -99 52.0 -99 -99 -99 1950 2016 normal 36 -99 52.0 -99 -99 -99 1950 2016 normal 48 -99 52.0 -99 -99 -99 1932,1950,1952 2016 normal 60 -99 52.0 -99 -99 -99 1933 2016,2018 normal