1991-2020 Degrees Fahrenheit 1 38.2 35.4 2.8 66 19 1977 1950 1973 1974 top-third 2 39.1 37.5 1.6 66 19 1977 1950,2002,2007 1974 1972 top-third 3 42.0 41.0 1.0 64 20 1977 2002 1973 1974 top-third 4 45.2 45.4 -0.2 53 31 1977 1950,2002 1973 1974 normal 1986,2019 5 49.7 50.4 -0.7 49 35 1977 2016 1973 1974 normal 6 53.9 54.8 -0.9 46 38 1977 2017 1973 1974 normal 1969,1985 7 57.2 58.3 -1.1 41 43 1977 2017 1973 1974 normal 1987,2010 8 58.7 60.3 -1.6 22 61 1977 2012,2017 1973 1974 bottom-third 1955,1984,1994 9 59.1 60.9 -1.8 17 66 1977 2012 1973 1974 bottom-third 1945,1984,1990,2004 10 58.9 60.4 -1.5 30 53 1977 2012 1973 1974 normal 1955,1980,1994 11 57.7 59.1 -1.4 33 50 1977 2013 1973 1974 normal 12 55.9 57.3 -1.4 33 50 1968 2013 1973 1974 normal 1943,1962 18 55.9 56.4 -0.5 53 29 1941 2013 1973 1974 normal 2014 24 56.6 57.2 -0.6 52 29 1968 2013 1974 1955 normal 2010 36 56.0 57.2 -1.2 27 52 1968 2013 1973 1974 normal 1973 48 56.2 57.2 -1.0 37 40 1964 2023 1973 1974 normal 1949,1957,1996 60 56.2 57.1 -0.9 36 39 1968 2021,2023 1974 1958 normal 1951,1998