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

Mattson Lake Water Temperature

Mattson Lake in Chisago County, Minnesota typically sits around 51°F at the surface in October — warmest in Jul (~79°F) and coldest in Oct (~51°F). That is a typical value for the month, not a live reading.

Typical in October
51°F
Cold
Summer average
76°F
Warmest (Jul)
79°F
Coldest (Oct)
51°F

Typical water temperature by month

Jan
Feb
Mar
Apr
65°
May
75°
Jun
79°
Jul
74°
Aug
69°
Sep
51°
Oct
Nov
Dec

Column height runs from this lake’s coldest month (51°F) to its warmest (79°F).

Typical surface water temperature by month, from 66 field readings (2017–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Mattson Lake warm enough to swim?

At its summer peak (~76°F): Comfortable

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

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

Where to stay near Mattson Lake

Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Mattson 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 Mattson 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 Mattson Lake?

Mattson Lake typically sits around 51°F at the surface in October, from 66 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.

When is Mattson Lake warmest?

Surface water at Mattson Lake is typically warmest in July, reaching about 79°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 Mattson Lake warm enough to swim?

At its typical summer peak of about 76°F, Mattson Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.

Where does this Mattson 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 — 66 readings from 2 monitoring stations between 2017 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.