Gunflint Lake Water Temperature
Gunflint Lake in Cook County, Minnesota typically sits around 58°F at the surface in September — warmest in Sep (~58°F) and coldest in May (~45°F). That is a typical value for the month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 181 field readings (2024–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Gunflint Lake warm enough to swim?
Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Want more than temperature? Gunflint Lake scored A on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.
Water temperatures at nearby Minnesota lakes
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Where to stay near Gunflint Lake
Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Gunflint Lake — live availability and prices. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Gunflint Lake
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Frequently asked questions
What is the water temperature of Gunflint Lake?
Gunflint Lake typically sits around 58°F at the surface in September, from 181 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
When is Gunflint Lake warmest?
Surface water at Gunflint Lake is typically warmest in September, reaching about 58°F. Lake surface temperature lags air temperature by several weeks, so the warmest water usually arrives in mid-to-late summer even though the hottest air can come earlier.
Is Gunflint Lake warm enough to swim?
At its typical summer peak of about 56°F, Gunflint Lake rates as "cold" for swimming. Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Where does this Gunflint Lake water temperature data come from?
Every temperature on this page is a typical (climatological) value computed from real surface-water field readings collected by state and federal agencies and published through the EPA Water Quality Portal — 181 readings from 2 monitoring stations between 2024 and 2025. They describe what is typical for each month, not the temperature right now.
About this data
Water temperatures are a climatology — the typical value for each month, averaged from real surface-water field readings collected by state and federal agencies and published through the EPA Water Quality Portal. They tell you what to expect, not the temperature at this moment. Actual conditions vary with recent weather, depth, and time of day.