I lived in San Antonio in the early 60s. My niece lives there now. It has a good in between moisture level.
If you are from El Paso, Arizona, New Mexico you might find San Antonio humid. If you are from Houston, deep East Texas, any of the southern states on the Gulf Coast, you will find San Antonio has a relatively dry climate. There is enough moisture for some greenery but not the lush greenery of the more humid rain filled areas.
There is always a risk of flash floods there. Since it is somewhat a roving hilly area this can be a problem at the bottom of the hills.
Actually San Antonio has a good southeast breeze. After dark in the summer, it will still be in the 90s but because of the lower humidities and that southeast breeze it is very comfortable. The same is true if you are in the shade during the summer. But if you stay out in that sun very long in the summer it can dehydratee you pretty fast.
I went to San Antonio during Hurricane Ike. One day when the storm was out in the gulf they had a humid day. Then the storm went another direction and it was very dry and pleasant.