1991-2020 Degrees Fahrenheit 1 60.5 63.5 -3.0 18 59 1967 2004 1950 1953 bottom-third 2 57.9 58.7 -0.8 41 36 1967 2019 1952 1953 normal 1976 3 52.3 53.5 -1.2 32 43 1967,1984 2012 1952 1953 normal 1963 4 49.2 49.1 0.1 52 23 1978 2012 1952 1953 top-third 1949,1999,2009 5 45.5 45.9 -0.4 48 27 1978 2023 1951 1953 normal 6 44.3 44.6 -0.3 52 22 1978 2012 1952 1953 top-third 1952,1957,1995,1997,2004 7 44.3 44.9 -0.6 46 27 1978 2012 1951 1953 normal 1957 8 45.9 46.5 -0.6 46 27 1978 2012 1951 1953 normal 1957 9 48.4 48.9 -0.5 46 27 1978 2012 1951 1953 normal 10 51.0 51.6 -0.6 48 25 1978 2023 1953 1953 normal 1953,1983,1995 11 53.3 54.0 -0.7 46 27 1963 2012 1951 1953 normal 1983,1992 12 54.9 55.5 -0.6 45 28 1963,1978 2012 1951 1953 normal 1992 18 51.8 51.8 0.0 50 20 1979 2017,2023 1953 1954 top-third 2003 24 55.1 55.4 -0.3 47 22 1978 2017,2023 1951 1954 top-third 2010 36 -99 55.4 -99 -99 -99 1979 2023 normal 48 -99 55.4 -99 -99 -99 1980 2023 normal 60 -99 55.3 -99 -99 -99 1967 2023 normal