St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake Water Temperature
St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake in Douglas County, Wisconsin averages about 70°F at the surface in summer — warmest in Jul (~77°F) and coldest in May (~58°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 9 field readings (2025–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake warm enough to swim?
Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Want more than temperature? St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake scored D on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.
Water temperatures at nearby Wisconsin lakes
Summer average ~65°F
Summer average ~72°F
Summer average ~73°F
Summer average ~72°F
Summer average ~74°F
Summer average ~74°F
Explore water temperatures
Where to stay near St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake
Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake — live availability and prices.
Top-rated places to stay near St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake
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 St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake — straight to your inbox. No spam, unsubscribe anytime.
Frequently asked questions
What is the water temperature of St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake?
St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake has a typical summer surface temperature of about 70°F. It is usually warmest in July (around 77°F) and coldest in May (around 58°F). These are typical values by month from 9 EPA Water Quality Portal field readings (2025–2025), not a live reading.
When is St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake warmest?
Surface water at St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake is typically warmest in July, reaching about 77°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 St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake warm enough to swim?
At its typical summer peak of about 70°F, St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Where does this St. Louis River Outlet Upstream of John A. Blatnik Memorial Bridge 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 — 9 readings from 1 monitoring station between 2025 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.