One of my favorite things to do in the Summer with my kids is to go to the movies. There's nothing like heading into a cold theatre in the hot of the Summer to escape the heat and see something entertaining. I have been known to nap during movies with my kids, and even bring my laptop along to work if I need to (the light from the screen isn't too bright in the back row!)
I love that our favorite movie theatre, The Alamo Drafthouse, has a kids camp each Summer where kids movies are $1 and you can't beat that to get out of the Austin sun!
If you are in Austin this Summer, plan to take in a movie at Alamo, where you can get coffee and your kids can get pizza. It doesn't get any better than that!