My children are older now, but we attempted to expose them to a variety of activities all summer long so as they grew they could discover what most interested them. I don't know how many of the following are operating esp due to the virus restrictions, but here are some we enjoyed over the years:
BV Children's museum & BV Natural History museum both had a variety of summer camps as did the George Bush Library.
Every one of my children progressed through the CS summer swim program and also were in a variety of their summer offerings--tennis, etc. Check the CS Parks and Rec website for what's available.
My oldest spent at least two summers participating in a week or so of activities at the ice rink.
Every one participated and enjoyed both the summer enrichment (through June) programs and the summer sports camps available through CSISD. They had a hard time picking which classes during enrichment there were so many different ones! Some were inside, some were outside. The microwave snack class was a big hit when that was offered. The sports camps were the same way. They did all of them at one time or another and many of them they participated in until they aged into the ms/hs camps. Usually, there was info through either the CSISD portal, or through the booster club sites.
There were also some camps they did through A&M but with a higher price tag, they only enrolled in their main interests for those. Sports, math camp, computer science, etc.
Millican Reserve had some programs too, I think, and they looked interesting, but we just never got around to them.
I'm sure I'm forgetting some of the places and activities, but overall, our children enjoyed their experiences and they aren't the most extroverted type of personality. Especially with the enrichment classes at the elementary schools, the instructors made it fun and friendly and age appropriate.
We also spent time exploring parks that were not in our neighborhood just for something different.
Best wishes for a fun and active summer.