1991-2020 Degrees Fahrenheit 1 36.4 33.2 3.2 70 14 1977 2023 1974 1953 top-third 2 37.5 35.8 1.7 69 15 1977 2016 1974 1950 top-third 3 40.9 39.5 1.4 69 14 1977 2016 1974 1950 top-third 4 44.1 44.0 0.1 59 24 1977 2016 1973 1974 top-third 2000,2019 5 48.7 49.1 -0.4 55 28 1977 2016 1973 1974 normal 6 53.2 53.6 -0.4 59 24 1977 2016 1973 1974 top-third 1995,2010 7 56.5 57.2 -0.7 58 25 1977 2016 1973 1974 top-third 1949 8 58.1 59.1 -1.0 50 32 1977 2016 1973 1974 normal 1976,1979,2003,2005,2010 9 58.5 59.6 -1.1 47 35 1977 2016 1973 1974 normal 1947,1952,1958,2003 10 58.1 59.1 -1.0 48 34 1977 2016 1973 1974 normal 1958 11 56.7 57.6 -0.9 47 34 1977 2016 1973 1974 normal 12 54.5 55.8 -1.3 42 39 1968 2013,2017 1973 1974 normal 18 54.5 55.0 -0.5 57 23 1945,1964,1978 2017 1974 1950 top-third 2005 24 55.1 55.7 -0.6 52 26 1969 2013 1974 1955 top-third 36 54.4 55.7 -1.3 36 39 1970 2022,2023 1973 1974 normal 1994 48 54.6 55.6 -1.0 39 33 1964,1970,1971 2023 1974 1958 normal 1952,1958,1995 60 54.5 55.6 -1.1 31 38 1970 2023 1974 1958 normal 1994,1996