1925-2000 Degrees Fahrenheit 1 0.7 2.2 -1.5 41 59 2012 1981 1999 1995 normal 2 -1.0 3.0 -4.0 16 83 1934 2001 1989 1999 bottom-third 3 2.0 5.9 -3.9 16 83 1943 2001 1989 1999 bottom-third 4 7.2 10.8 -3.6 15 84 1934 2003 1989 1999 bottom-third 2012 5 14.2 16.7 -2.5 16 83 1934 2003 1997 1999 bottom-third 2012 6 20.3 22.2 -1.9 18 81 1934 2003 1997 1999 bottom-third 7 25.0 26.6 -1.6 19 80 1934 2003 1997 1999 bottom-third 1974,2009 8 28.3 29.4 -1.1 21 78 1934 2003 1997 1999 bottom-third 1946 9 29.3 30.3 -1.0 25 74 1934 2003 1997 1999 bottom-third 1928 10 28.7 29.6 -0.9 28 71 1956 2018 1997 1999 bottom-third 11 26.9 27.9 -1.0 21 78 1956 2016 1976 1999 bottom-third 1932 12 24.4 26.0 -1.6 15 84 1956 2020 1976 1999 bottom-third 18 23.6 24.7 -1.1 15 83 1957,1972 2020 1976 1999 bottom-third 1962 24 26.2 26.0 0.2 38 60 1957 2017 1997 1999 normal 1961,1987,1997 36 26.9 25.9 1.0 65 32 1957 2017,2018 1998 1999 top-third 1928,1937,1990,1992,1998,2002 48 26.5 25.9 0.6 45 51 1975 2020 1993 1999 normal 1979,1987,1992 60 26.6 25.9 0.7 52 43 1976 2020 1993 1999 normal 1931,1939,1990,2012