Astros Had The 2nd Highest Team SLG For A Month In July Since 1913 At .568 (minimum of 20 games)

Data from the Baseball Reference Play Index.

Team	Month	Year	G	SLG	SLG
NYY	June	1930	28	0.593	0.592522
HOU	July	2017	24	0.568	0.567816
STL	April/March	2000	25	0.568	0.567599
BOS	June	2003	26	0.556	0.556468
ATL	July	2006	24	0.554	0.554007
SEA	May	1999	27	0.549	0.549428
CLE	July	1936	33	0.546	0.546252
TEX	Sept/Oct	2011	25	0.544	0.543624
CLE	April/March	1997	25	0.543	0.543430
SFG	June	2000	26	0.539	0.539037

Now the OPS leaders

Team	Split	Year	G	OPS	R	BA	OBP	SLG
NYY	June	1930	28	1.035	261	0.366	0.442	0.593
STL	April/Mar	2000	25	0.959	180	0.301	0.392	0.568
HOU	July	2017	24	0.948	174	0.323	0.38	0.568
BOS	June	2003	26	0.945	190	0.315	0.388	0.556
CLE	April/Mar	1997	25	0.942	167	0.305	0.399	0.543
CLE	July	1936	33	0.94	244	0.352	0.394	0.546
SEA	May	1999	27	0.935	191	0.308	0.386	0.549
SFG	June	2000	26	0.932	175	0.309	0.393	0.539
STL	July	1928	29	0.931	188	0.32	0.401	0.529
NYY	May	1936	28	0.929	218	0.309	0.395	0.534

Here are the stats for the Yankees in June 1930. They were 20-8, allowing 160 runs. Ruth and Gehrig are the only teammates to have an SLG of at least .900 in the same month, 75+ PAs. First guy not named Ruth to do it is Chick Hafey in 1928 (July) at .925.

Player	HR	RBI	BA	OBP	SLG	OPS	PA	AB
Babe Ruth	15	35	0.392	0.560	0.918	1.477	137	97
Lou Gehrig	10	42	0.495	0.582	0.919	1.501	137	111
Ben Chapman	2	18	0.346	0.421	0.514	0.936	123	107
Tony Lazzeri	3	34	0.352	0.424	0.562	0.986	121	105
Earle Combs	2	17	0.440	0.505	0.692	1.197	105	91
Harry Rice	1	18	0.366	0.398	0.505	0.903	101	93
Bill Dickey	1	23	0.439	0.483	0.610	1.093	92	82
Lyn Lary	0	9	0.185	0.264	0.277	0.541	76	65
Samuel Byrd	1	9	0.474	0.545	0.632	1.177	44	38
Jimmie Reese	1	6	0.238	0.238	0.333	0.571	44	42
Dusty Cooke	3	9	0.343	0.395	0.714	1.109	38	35
Yats Wuestling	0	1	0.231	0.231	0.308	0.538	27	26
Bubbles Hargrave	0	2	0.286	0.348	0.429	0.776	24	21
George Pipgras	0	4	0.158	0.238	0.263	0.501	22	19
Red Ruffing	0	2	0.474	0.500	0.579	1.079	20	19
Herb Pennock	0	4	0.467	0.529	0.467	0.996	18	15
Ed Wells	0	1	0.333	0.375	0.333	0.708	17	15
Billy Werber	0	2	0.286	0.412	0.286	0.697	17	14
Benny Bengough	0	1	0.308	0.357	0.538	0.896	15	13
Roy Sherid	0	2	0.167	0.286	0.167	0.452	15	12
Hank Johnson	1	6	0.385	0.429	0.923	1.352	14	13
Ownie Carroll	0	1	0.333	0.333	0.333	0.667	7	6