1991-2020 Degrees Fahrenheit 1 32.4 34.9 -2.5 30 47 2015 2017 1942 1944 normal 1959 2 28.2 33.7 -5.5 11 66 1978 2023 1940 1944 bottom-third 3 28.7 34.9 -6.2 5 71 1963 2002 1945 1944 bottom-tenth 4 32.6 37.7 -5.1 8 68 1977 2002 1945 1944 bottom-tenth 5 36.9 41.6 -4.7 6 70 1977 2002 1945 1944 bottom-tenth 6 42.0 46.3 -4.3 5 70 1977 2017 1945 1944 bottom-tenth 1978 7 46.8 50.6 -3.8 8 67 1977 2017 1941 1944 bottom-third 8 50.7 53.9 -3.2 10 65 1977 2017 1941 1944 bottom-third 9 53.1 56.1 -3.0 11 64 1977 2017 1941 1944 bottom-third 1948 10 54.8 56.9 -2.1 26 49 1977 2017 1941 1944 normal 1940 11 54.3 56.7 -2.4 21 54 1977 2017 1941 1944 bottom-third 12 52.9 55.6 -2.7 13 62 1941 2017 1941 1944 bottom-third 1964,1967 18 49.7 52.4 -2.7 11 62 1941,1968 2017 1941 1944 bottom-third 1977,2015 24 53.2 55.5 -2.3 17 56 1941,1968 2017 1942 1944 bottom-third 36 53.4 55.5 -2.1 16 55 1963 2023 1943 1944 bottom-third 1953,1962,1980,1981 48 53.7 55.5 -1.8 26 43 1964 2023 1944 1945 normal 1947,1972,1977,1984 60 53.2 55.5 -2.3 12 55 1965 2023 1945 1944 bottom-third 1962,1979,1980