Lake of the Isles Water Temperature
Lake of the Isles in Hennepin County, Minnesota averages about 62°F at the surface in summer — warmest in Jul (~63°F) and coldest in Jan (~37°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 1,192 field readings (2010–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Lake of the Isles warm enough to swim?
Brisk but swimmable for short dips — most people acclimate after the first few minutes.
Want more than temperature? Lake of the Isles 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
Explore water temperatures
Where to stay near Lake of the Isles
Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Lake of the Isles — live availability and prices.
Top-rated places to stay near Lake of the Isles
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 Lake of the Isles?
Get lake water-quality report cards plus the best cabin & lodging deals near Lake of the Isles — straight to your inbox. No spam, unsubscribe anytime.
Frequently asked questions
What is the water temperature of Lake of the Isles?
Lake of the Isles has a typical summer surface temperature of about 62°F. It is usually warmest in July (around 63°F) and coldest in January (around 37°F). These are typical values by month from 1,192 EPA Water Quality Portal field readings (2010–2025), not a live reading.
When is Lake of the Isles warmest?
Surface water at Lake of the Isles is typically warmest in July, reaching about 63°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 Lake of the Isles warm enough to swim?
At its typical summer peak of about 62°F, Lake of the Isles rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.
Where does this Lake of the Isles 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 — 1,192 readings from 3 monitoring stations between 2010 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.