Half Moon Lake Water Temperature
Half Moon Lake in Hennepin County, Minnesota averages about 59°F at the surface in summer — warmest in Jul (~60°F) and coldest in Jan (~36°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 973 field readings (2010–2024) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Half Moon Lake warm enough to swim?
Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Want more than temperature? Half Moon Lake scored D 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 ~57°F
Summer average ~56°F
Summer average ~60°F
Summer average ~61°F
Summer average ~57°F
Summer average ~50°F
Explore water temperatures
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Frequently asked questions
What is the water temperature of Half Moon Lake?
Half Moon Lake has a typical summer surface temperature of about 59°F. It is usually warmest in July (around 60°F) and coldest in January (around 36°F). These are typical values by month from 973 EPA Water Quality Portal field readings (2010–2024), not a live reading.
When is Half Moon Lake warmest?
Surface water at Half Moon Lake is typically warmest in July, reaching about 60°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 Half Moon Lake warm enough to swim?
At its typical summer peak of about 59°F, Half Moon Lake rates as "cold" for swimming. Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Where does this Half Moon 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 — 973 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.