Big Marine Lake Water Temperature
Big Marine Lake in Washington County, Minnesota typically sits around 54°F at the surface in October — warmest in Aug (~70°F) and coldest in Apr (~45°F). That is a typical value for the month, not a live reading.
Typical water temperature by month
Column height runs from this lake’s coldest month (45°F) to its warmest (70°F).
Typical surface water temperature by month, from 313 field readings (2010–2024) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Big Marine Lake warm enough to swim?
Brisk but swimmable for short dips — most people acclimate after the first few minutes.
Want more than temperature? Big Marine Lake water quality: clarity, algae, phosphorus, depth, fish species, and current advisories, all on one page.
Water temperatures at nearby Minnesota lakes
Summer average ~76°F
Summer average ~70°F
Summer average ~72°F
Summer average ~57°F
Summer average ~60°F
Summer average ~60°F
Explore water temperatures
Where to stay near Big Marine Lake
Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Big Marine 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 Big Marine Lake
Prices for Oct 23–25, 4 adults. Change dates on the map below.
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Frequently asked questions
What is the water temperature of Big Marine Lake?
Big Marine Lake typically sits around 54°F at the surface in October, from 313 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
When is Big Marine Lake warmest?
Surface water at Big Marine Lake is typically warmest in August, reaching about 70°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 Big Marine Lake warm enough to swim?
At its typical summer peak of about 67°F, Big Marine Lake rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.
Where does this Big Marine 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 — 313 readings from 1 monitoring station 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.