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

Beltrami Lake Water Temperature

Beltrami Lake in Beltrami County, Minnesota typically sits around 66°F at the surface in September — warmest in Jul (~74°F) and coldest in May (~55°F). That is a typical value for the month, not a live reading.

Typical in September
66°F
Cool
Summer average
70°F
Warmest (Jul)
74°F
Coldest (May)
55°F

Typical water temperature by month

Jan
Feb
Mar
Apr
55°
May
69°
Jun
74°
Jul
66°
Aug
66°
Sep
Oct
Nov
Dec

Column height runs from this lake’s coldest month (55°F) to its warmest (74°F).

Typical surface water temperature by month, from 97 field readings (2018–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Beltrami Lake warm enough to swim?

At its summer peak (~70°F): Comfortable

Pleasant for swimming — the range most people find enjoyable without a wetsuit.

Want more than temperature? Beltrami Lake water quality: clarity, algae, phosphorus, depth, fish species, and current advisories, all on one page.

Where to stay near Beltrami Lake

Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Beltrami 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 Beltrami 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.

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Frequently asked questions

What is the water temperature of Beltrami Lake?

Beltrami Lake typically sits around 66°F at the surface in September, from 97 EPA Water Quality Portal field readings (2018–2025). That is a typical value for the month, not a live reading.

When is Beltrami Lake warmest?

Surface water at Beltrami Lake is typically warmest in July, reaching about 74°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 Beltrami Lake warm enough to swim?

At its typical summer peak of about 70°F, Beltrami Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.

Where does this Beltrami 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 — 97 readings from 2 monitoring stations between 2018 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.