Deserat,
July/August in San Antonio!! Yikes. You could not pay me to be there in high summer. Heat is oppressive, humid, no breeze, even hot at night. The only place worse is Houston or maybe Dallas.
If you can, schedule a few trips out of town to the hill county up towards Austin while you are there. The heat is a bit drier and it is interesting countryside. There are few if any places cool in Texas in the summer.
Now spring, summer and most of winter are exceptional! That is why we are still in South Texas. We plan on visiting high country Colorado for July or August this year.
2fer