1991-2020 Degrees Fahrenheit 1 70.9 74.4 -3.5 17 105 1987 2015 1895 1895 bottom-third 2 69.3 72.2 -2.9 29 92 1931 2015 1895 1895 bottom-third 1937 3 65.6 70.4 -4.8 8 112 1958 2023 1895 1895 bottom-tenth 1940,2010 4 65.1 68.8 -3.7 14 101 1958 2023 1895 1895 bottom-third 1960,1983,1996 5 -99 68.5 -99 -99 -99 1958 2023 normal 6 -99 68.9 -99 -99 -99 1958 2023 normal 7 -99 70.2 -99 -99 -99 1958 2020 normal 8 -99 71.6 -99 -99 -99 1958 2020 normal 9 -99 72.9 -99 -99 -99 1958 2020 normal 10 -99 73.9 -99 -99 -99 1958 2020,2023 normal 11 -99 74.6 -99 -99 -99 1958,1977 2020,2023 normal 12 -99 75.0 -99 -99 -99 1977 2020,2023 normal 18 -99 72.8 -99 -99 -99 1978 2023 normal 24 -99 74.9 -99 -99 -99 1978 2021,2023 normal 36 -99 74.8 -99 -99 -99 1970,1971 2022 normal 48 -99 74.7 -99 -99 -99 1969,1970,1971 2023 normal 60 -99 74.7 -99 -99 -99 1970 2023 normal