1991-2020 Degrees Fahrenheit 1 55.0 57.9 -2.9 17 60 1958 1974 2001 2000 bottom-third 2 50.7 53.9 -3.2 14 63 1958 2017 2001 2000 bottom-third 1964 3 50.0 51.3 -1.3 33 43 1978 2000,2017 2001 2000 normal 1964,1980,1982,1997 4 49.7 50.2 -0.5 37 38 1978 2000 2001 2000 normal 5 51.6 51.2 0.4 48 27 2001 2000 2001 2000 normal 1990 6 54.0 53.8 0.2 44 31 1977 2017 2001 2000 normal 1971,2007,2011 7 57.0 57.1 -0.1 35 40 1977,2010 2017 2001 2000 normal 1981,1991 8 60.4 60.4 0.0 40 35 1977 2000,2017 2001 2000 normal 1966,2018 9 63.5 63.1 0.4 52 23 1977 2017 2001 2000 top-third 1963,2011 10 65.4 64.9 0.5 52 23 1977 2017 2001 2000 top-third 1956 11 66.2 65.7 0.5 54 21 1977 1999 2001 2000 top-third 2009 12 66.1 65.7 0.4 50 25 1977 2012 2001 2000 top-third 1965,1971,2009 18 60.8 61.7 -0.9 16 57 1959,1960 2023 1998 2001 bottom-third 1989,1996,2011 24 65.6 65.7 -0.1 40 33 1978 2000 1998 2001 normal 1979,1980,2009 36 66.3 65.7 0.6 55 16 1960 1955,1957 1999 2001 top-third 1951,2019 48 66.7 65.6 1.1 63 6 1996 1955 2001 1957 top-tenth 60 66.2 65.6 0.6 54 13 1996 1957 2001 1967 top-third 2003,2017,2019,2021