St. Clair Lake Water Temperature
St. Clair Lake in Becker County, Minnesota averages about 72°F at the surface in summer — warmest in Jul (~75°F) and coldest in Sep (~67°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 223 field readings (2016–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is St. Clair Lake warm enough to swim?
Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Want more than temperature? St. Clair 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
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Frequently asked questions
What is the water temperature of St. Clair Lake?
St. Clair Lake has a typical summer surface temperature of about 72°F. It is usually warmest in July (around 75°F) and coldest in September (around 67°F). These are typical values by month from 223 EPA Water Quality Portal field readings (2016–2025), not a live reading.
When is St. Clair Lake warmest?
Surface water at St. Clair 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 St. Clair Lake warm enough to swim?
At its typical summer peak of about 72°F, St. Clair Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Where does this St. Clair 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 — 223 readings from 3 monitoring stations between 2016 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.