Grant Lake Water Temperature
Grant Lake in Beltrami County, Minnesota averages about 57°F at the surface in summer — warmest in Jun (~66°F) and coldest in Aug (~48°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 107 field readings (2016–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Grant Lake warm enough to swim?
Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Want more than temperature? Grant Lake scored A 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 ~68°F
Summer average ~73°F
Summer average ~68°F
Summer average ~61°F
Summer average ~73°F
Summer average ~64°F
Explore water temperatures
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Frequently asked questions
What is the water temperature of Grant Lake?
Grant Lake has a typical summer surface temperature of about 57°F. It is usually warmest in June (around 66°F) and coldest in August (around 48°F). These are typical values by month from 107 EPA Water Quality Portal field readings (2016–2025), not a live reading.
When is Grant Lake warmest?
Surface water at Grant Lake is typically warmest in June, reaching about 66°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 Grant Lake warm enough to swim?
At its typical summer peak of about 57°F, Grant Lake rates as "cold" for swimming. Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Where does this Grant 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 — 107 readings from 1 monitoring station 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.