Superior Lake Water Temperature
Superior Lake in Cook County, Minnesota typically sits around 57°F at the surface in September — warmest in Sep (~57°F) and coldest in May (~40°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 1,298 field readings (2016–2024) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Superior Lake warm enough to swim?
Cold-water shock is a real risk below 50°F — unprotected swimming is unsafe and even strong swimmers can lose muscle control within minutes.
Want more than temperature? Superior Lake scored NR 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 Superior Lake
Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Superior 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 Superior Lake
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Frequently asked questions
What is the water temperature of Superior Lake?
Superior Lake typically sits around 57°F at the surface in September, from 1,298 EPA Water Quality Portal field readings (2016–2024). That is a typical value for the month, not a live reading.
When is Superior Lake warmest?
Surface water at Superior Lake is typically warmest in September, reaching about 57°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 Superior Lake warm enough to swim?
At its typical summer peak of about 49°F, Superior Lake rates as "very cold" for swimming. Cold-water shock is a real risk below 50°F — unprotected swimming is unsafe and even strong swimmers can lose muscle control within minutes.
Where does this Superior 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 — 1,298 readings from 6 monitoring stations between 2016 and 2024. 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.