The bats should be in peak season. Check out the Congress Ave bridge at dusk to see over 1 million bats make their nightly descent on the city. They actually eat all of the mosquitoes by the river, so go ahead and shout out a thank you to them as they fly by. Truly a very cool experience. Don’t worry they won’t come anywhere near you!
Immediately downstream from Austin’s famous Barton Springs, Barkin Springs is a free dog friendly alternative spot to swim! Park near Zilker and walk to this spot and you will find humans and dogs galore beating the heat by swimming in the creek and drinking cold beer (byob).