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LakeQuality
A wave breaking on the cobble beach of Lake Superior at Duluth, Minnesota, with a wooded headland beyond

Superior Lake Water Temperature

Superior Lake in Cook County, Minnesota typically sits around 49°F at the surface in October — warmest in Sep (~57°F) and coldest in May (~40°F). That is a typical value for the month, not a live reading.

Typical in October
49°F
Very cold
Summer average
49°F
Warmest (Sep)
57°F
Coldest (May)
40°F

Typical water temperature by month

Jan
Feb
Mar
Apr
40°
May
43°
Jun
48°
Jul
56°
Aug
57°
Sep
49°
Oct
Nov
Dec

Column height runs from this lake’s coldest month (40°F) to its warmest (57°F).

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?

At its summer peak (~49°F): Very cold

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 water quality: clarity, algae, phosphorus, depth, fish species, and current advisories, all on one page.

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

Prices for Oct 23–25, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a trip to Superior Lake?

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Frequently asked questions

What is the water temperature of Superior Lake?

Superior Lake typically sits around 49°F at the surface in October, 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.