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

Wilmes Lake Water Temperature

Wilmes Lake in Washington County, Minnesota typically sits around 62°F at the surface in September — warmest in Jul (~66°F) and coldest in Apr (~44°F). That is a typical value for the month, not a live reading.

Typical in September
62°F
Cool
Summer average
64°F
Warmest (Jul)
66°F
Coldest (Apr)
44°F

Typical water temperature by month

Jan
Feb
Mar
Apr
44°
May
52°
Jun
61°
Jul
66°
Aug
64°
Sep
62°
Oct
56°
Nov
Dec

Typical surface water temperature by month, from 158 field readings (20102024) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Wilmes Lake warm enough to swim?

At its summer peak (~64°F): Cool

Brisk but swimmable for short dips — most people acclimate after the first few minutes.

Want more than temperature? Wilmes Lake scored F on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.

Where to stay near Wilmes Lake

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

Prices for Sep 4–6, 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 Wilmes Lake?

Get lake water-quality report cards plus the best cabin & lodging deals near Wilmes Lake — straight to your inbox. No spam, unsubscribe anytime.

Frequently asked questions

What is the water temperature of Wilmes Lake?

Wilmes Lake typically sits around 62°F at the surface in September, from 158 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.

When is Wilmes Lake warmest?

Surface water at Wilmes Lake is typically warmest in July, reaching about 66°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 Wilmes Lake warm enough to swim?

At its typical summer peak of about 64°F, Wilmes Lake rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.

Where does this Wilmes 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 — 158 readings from 2 monitoring stations between 2010 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.