1991-2020 Degrees Fahrenheit 1 43.2 44.6 -1.4 43 37 1978 2017 1948 1949 normal 2 46.9 43.0 3.9 74 6 1978 2023 1948 1949 top-tenth 3 45.5 43.5 2.0 70 10 1978 2017 1948 1949 top-third 1957 4 46.0 45.4 0.6 61 19 1977 2023 1948 1949 top-third 5 49.4 48.6 0.8 66 14 1977 2017 1949 1949 top-third 1949,2021 6 52.5 52.5 0.0 58 22 1977 2017 1948 1949 top-third 7 56.0 56.2 -0.2 60 20 1977 2017 1949 1950 top-third 1976,2011,2013 8 59.1 59.2 -0.1 59 21 1977 2017 1949 1950 top-third 2000 9 60.9 61.1 -0.2 58 22 1977 2017 1949 1950 top-third 10 61.5 61.8 -0.3 58 21 1968 2017,2020 1949 1950 top-third 11 61.1 61.7 -0.6 56 23 1968,1977 2020 1948 1949 top-third 12 60.1 60.8 -0.7 53 26 1968 2017 1948 1949 top-third 1986,1987,2010 18 57.7 58.0 -0.3 57 22 1968 2017 1949 1950 top-third 24 60.3 60.8 -0.5 55 23 1964,1968 2017 1949 1950 top-third 2014 36 59.2 60.7 -1.5 34 43 1970 2018 1949 1950 normal 48 59.1 60.7 -1.6 32 44 1970 2020 1949 1950 normal 1953,1954 60 59.2 60.6 -1.4 33 42 1970 2020 1950 1950 normal 1987