National Weather Service United States Department of Commerce

Swim risk will be low for the Labor Day weekend, though water temperatures are quite cool in the 50s and 60s. Expect plenty of sunshine with warming temperatures through the weekend.
Water temperatures along the Lake Michigan shoreline range from the mid 50s to mid 60s. It's important to watch for hypothermia when the water gets cold as body heat is lost 25 times faster in cold water than cold air.