1991-2020 Degrees Fahrenheit 1 68.5 65.6 2.9 83 10 1931 2020 1944 1945 top-third 2 63.9 62.6 1.3 80 12 1947 2017 1944 1945 top-third 3 60.3 60.4 -0.1 65 26 1978 2017 1944 1935 top-third 1976,2011 4 58.4 59.7 -1.3 44 47 1978 2017 1944 1939 normal 1933 5 59.2 60.5 -1.3 48 43 1978 2017 1944 1935 normal 1993 6 -99 62.7 -99 -99 -99 1977 2017 normal 7 -99 65.5 -99 -99 -99 1977 2017 normal 8 -99 68.1 -99 -99 -99 1977 2017 normal 9 -99 70.0 -99 -99 -99 1977 2017 normal 10 -99 71.4 -99 -99 -99 1977 2017 normal 11 -99 72.0 -99 -99 -99 1977 2017 normal 12 -99 72.0 -99 -99 -99 1977 2017 normal 18 -99 68.9 -99 -99 -99 1978 2017 normal 24 -99 72.0 -99 -99 -99 1978 2017 normal 36 -99 72.0 -99 -99 -99 1979 2018 normal 48 -99 72.0 -99 -99 -99 1980 2019,2020 normal 60 -99 72.0 -99 -99 -99 1980,1981 2020 normal