Some other great months, the pennant winning 1935 Cubs stormed to the NL pennant with a 21 game winning streak in September and a 23-3 record overall that month. And 2 of the losses came on the last 2 days of the season after the Cubs had already clinched the pennant.SumnerH said:
1916 Giants went 29-5-2 in September.
http://www.baseball-reference.com/teams/NYG/1916-schedule-scores.shtml
The 2002 A's had a 24-4 month of August though the famous 20 game winning streak extended into the first couple days of September.
Looking at some of the memorable Sox teams of the past, none of them came up with a month to quite match those.
Year---Best Month
1912 21-8 June
1915 21-6 August
1946 21-6 May
1948 25-9 July
1949 23-8 August and 19-5 September
1950 24-6 August
1967 19-10 July
1972 20-9 September
1975 22-11 July
1977 22-8 September
1978 23-7 May
1986 21-7 May
2004 21-7 August
2007 20-8 May