What Is Lake Michigan’s Ideal Swimming Temperature?

You know when there is a string of days in a row where the temperatures outside are in the upper 70s, lower 80s, or even in the 90s (😱) and the only place you want to go is the beach and take refuge in Lake Michigan? Have you ever gotten to the beach, sprinted in the water, and instantly turned back around because the water was freezing cold? 

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It feels wrong when it can be so hot outside the water but so cold once you're in the water, that you almost have to choose which struggle to put up with. When this happens, it can be confusing because you're expecting the water not to be freezing. So, when is Lake Michigan considered a good swimming temperature, and how long will you have to wait until then?

Lake Michigan Swimming Temperatures

Unless you're crazy and enjoy doing a polar plunge, you probably don't go into the lake expecting to be cold. Sure, cooling off is the goal, but shivering is not. On the posting date (May 14th, 2025), the National Oceanic and Atmospheric Administration (NOAA) reports that Lake Michigan's temperature is around 45°F. If that sounds cold, that's because it is. The southernmost part of Lake Michigan is around 55°F. That sounds better, but it's actually still below the "ideal temp".

READ MORE: Lake Michigan Water Levels Drop as Great Lakes Fall Below Normal |

Sea Temperature, a site that tracks water temperatures around the globe, states that water temperatures below 69.8°F "may be too cold for extended swimming." However, the real concern comes when you swim in water below 59°F. At this temperature, you run the risk of hypothermia, and wearing a wetsuit is encouraged.

When Is The Best Time For Swimming?

According to the averages of the Lake Michigan water temperatures:

Average June Temp: 58.1°F

Average July Temp: 66.7°F

Average August Temp: 68°F

Based on this, July and August are when Lake Michigan is at its warmest and has the best swimming temperatures. June is still on the cooler end, unless there is a streak of hot days in a row.

It is important to keep in mind that water temperature heats more slowly than air temperature because water is denser than air. So it can take a day or two of sustained high temperatures to really warm up the water.