1991-2020 Degrees Fahrenheit 1 32.4 32.5 -0.1 47 30 1977 2023 1945 1944 normal 2 30.8 34.9 -4.1 22 54 1961 2002 1945 1944 bottom-third 3 35.4 38.7 -3.3 19 57 1977 2002,2016 1945 1944 bottom-third 1978,2011 4 40.1 43.3 -3.2 19 57 1977 2002 1945 1944 bottom-third 5 45.8 48.6 -2.8 23 52 1977 2016 1945 1943 bottom-third 1943,1987 6 50.3 53.2 -2.9 18 57 1977 2016 1945 1944 bottom-third 1944 7 53.8 56.7 -2.9 15 60 1977 2017 1945 1944 bottom-third 1940 8 56.1 58.8 -2.7 16 59 1977 2017 1945 1944 bottom-third 1973,1987 9 56.6 59.4 -2.8 12 63 1977 2016 1941 1945 bottom-third 1948 10 56.4 58.9 -2.5 16 59 1977 2016 1941 1945 bottom-third 1967 11 56.0 57.5 -1.5 41 34 1977 2017 1945 1942 normal 1953,1956,1958,1969,1978,2014 12 54.1 55.6 -1.5 41 34 1968 2013 1945 1942 normal 1949,1955,1956,1971 18 52.5 54.7 -2.2 24 49 1941,1964,1968 2017 1945 1943 bottom-third 1981,2004,2015 24 53.5 55.5 -2.0 25 48 1964,1968 2013 1945 1944 normal 1948,1958,1961,1979 36 53.5 55.5 -2.0 21 50 1963,1965 2023 1945 1944 bottom-third 1952,1962,1971 48 53.5 55.5 -2.0 22 47 1964 2023 1944 1945 bottom-third 1948,1960,1983,1984 60 53.7 55.5 -1.8 29 38 1965,1968 2023 1945 1946 normal 1951,1955