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

Long Lake Water Temperature

Long Lake in Waupaca County, Wisconsin typically sits around 72°F at the surface in August — warmest in Jul (~75°F) and coldest in May (~58°F). That is a typical value for the month, not a live reading.

Typical in August
72°F
Comfortable
Summer average
73°F
Warmest (Jul)
75°F
Coldest (May)
58°F

Typical water temperature by month

Jan
Feb
Mar
Apr
60°
May
58°
Jun
71°
Jul
75°
Aug
72°
Sep
Oct
Nov
Dec

Typical surface water temperature by month, from 23 field readings (20242026) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Long Lake warm enough to swim?

At its summer peak (~73°F): Comfortable

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

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

Where to stay near Long Lake

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

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

Frequently asked questions

What is the water temperature of Long Lake?

Long Lake typically sits around 72°F at the surface in August, from 23 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.

When is Long Lake warmest?

Surface water at Long Lake is typically warmest in July, reaching about 75°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 Long Lake warm enough to swim?

At its typical summer peak of about 73°F, Long Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.

Where does this Long 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 — 23 readings from 1 monitoring station between 2024 and 2026. 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.