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

Elmo Lake Water Temperature

Elmo Lake in Washington County, Minnesota typically sits around 51°F at the surface in September — warmest in Jul (~80°F) and coldest in Apr (~40°F). That is a typical value for the month, not a live reading.

Typical in September
51°F
Cold
Summer average
63°F
Warmest (Jul)
80°F
Coldest (Apr)
40°F

Typical water temperature by month

Jan
Feb
Mar
Apr
40°
May
44°
Jun
57°
Jul
80°
Aug
52°
Sep
51°
Oct
46°
Nov
Dec

Typical surface water temperature by month, from 598 field readings (20102025) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Elmo Lake warm enough to swim?

At its summer peak (~63°F): Cool

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

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

Where to stay near Elmo Lake

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

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Frequently asked questions

What is the water temperature of Elmo Lake?

Elmo Lake typically sits around 51°F at the surface in September, from 598 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.

When is Elmo Lake warmest?

Surface water at Elmo Lake is typically warmest in July, reaching about 80°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 Elmo Lake warm enough to swim?

At its typical summer peak of about 63°F, Elmo Lake rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.

Where does this Elmo 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 — 598 readings from 2 monitoring stations between 2010 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.