Great Lakes Water Temperature by Month (and What Wetsuit to Wear)

How cold is the water in the Great Lakes? It depends on the lake, the month and the wind. Here are average water temperatures by month for all five lakes, and what wetsuit to wear for each.

Average water temperature by month (°F)

Averages near shore at one city on each lake.

Cities: Superior at Duluth, Michigan at Chicago, Huron at Port Huron, Erie at Cleveland, Ontario at Toronto.

What the numbers mean

• Lake Superior is the coldest. Even in August it only averages the mid-60s at Duluth, and much of the surf season is in the 30s and 40s.
• Lake Erie is the warmest because it's the shallowest. It also cools fast in fall and often freezes over in winter.
• Lakes Michigan, Huron and Ontario sit in between, peaking around 70°F in August and dropping into the 30s by midwinter.
• Upwelling can change everything. A strong offshore wind can push warm surface water away and drop nearshore temperatures by 10 to 20°F or more within a day, even in summer.

What wetsuit to wear

Most good Great Lakes surf comes from October to April, when the water is in the 30s to 50s. That means a hooded 5/4 or warmer for most of the season. If you can only own one suit for lake surfing, buy the warm one. More in our cold water wetsuit guide and winter surfing tips.

Lake guides

Lake Michigan · Chicago · Lake Superior · Lake Ontario and Toronto · Great Lakes Surfing FAQ

For after the session

Skull Cap Hoodie
For the walk back to the car.

Frozen Break T-Shirt
For the ones who surf through the freeze.

Water temperatures: 10-year monthly averages from seatemperature.info (Duluth, Chicago, Port Huron, Cleveland and Toronto stations), rounded to the nearest degree.