The Bob Welch Aquatic Center is a great place to swim in the summer, and features a kiddie pool, concession stand, and water slide. There are free swimming areas at Michael La Canne Memorial Park in Goodview and Latsch Island, but please note there is no lifeguard at these locations. Remember the Mississippi River current is strong and can be dangerous.
The Winona YMCA has two indoor pools and non-members/visitors can purchase a day pass to use them during their open hours (check their website or call them to confirm available hours). A waiver release is required.
In about a twenty minute drive, there is a large outdoor swimming pond available at Money Creek Haven Campground during the summer months. There is a day use fee for school-aged kids and over.
Thirty minutes away near Saint Charles is Whitewater State Park and they have an outdoor swimming beach area on the Whitewater. Visitors need a vehicle pass.