Johnson Lake Water Temperature
Johnson Lake in Clearwater County, Minnesota typically sits around 51°F at the surface in September — warmest in Jul (~52°F) and coldest in May (~48°F). That is a typical value for the month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 561 field readings (2011–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Johnson Lake warm enough to swim?
Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Want more than temperature? Johnson 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
Explore water temperatures
Where to stay near Johnson Lake
Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Johnson 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 Johnson Lake
Prices for Sep 4–6, 4 adults. Change dates on the map below.
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 Johnson Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near Johnson Lake — straight to your inbox. No spam, unsubscribe anytime.
Frequently asked questions
What is the water temperature of Johnson Lake?
Johnson Lake typically sits around 51°F at the surface in September, from 561 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
When is Johnson Lake warmest?
Surface water at Johnson Lake is typically warmest in July, reaching about 52°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 Johnson Lake warm enough to swim?
At its typical summer peak of about 51°F, Johnson Lake rates as "cold" for swimming. Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Where does this Johnson 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 — 561 readings from 1 monitoring station between 2011 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.