Clear Lake Water Temperature
Clear Lake in Washington County, Minnesota averages about 69°F at the surface in summer — warmest in Aug (~72°F) and coldest in Feb (~39°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 689 field readings (2010–2024) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Clear Lake warm enough to swim?
Brisk but swimmable for short dips — most people acclimate after the first few minutes.
Want more than temperature? Clear Lake scored C on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.
Water temperatures at nearby Minnesota lakes
Summer average ~74°F
Summer average ~59°F
Summer average ~69°F
Summer average ~62°F
Summer average ~54°F
Summer average ~75°F
Explore water temperatures
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Frequently asked questions
What is the water temperature of Clear Lake?
Clear Lake has a typical summer surface temperature of about 69°F. It is usually warmest in August (around 72°F) and coldest in February (around 39°F). These are typical values by month from 689 EPA Water Quality Portal field readings (2010–2024), not a live reading.
When is Clear Lake warmest?
Surface water at Clear Lake is typically warmest in August, reaching about 72°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 Clear Lake warm enough to swim?
At its typical summer peak of about 69°F, Clear Lake rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.
Where does this Clear 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 — 689 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.