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LakeQuality

Three Island Lake Water Temperature

Three Island Lake in Itasca County, Minnesota averages about 69°F at the surface in summer — warmest in Aug (~73°F) and coldest in Sep (~60°F). These are typical values by month, not a live reading.

Typical in July
Summer average
69°F
Warmest (Aug)
73°F
Coldest (Sep)
60°F

Typical water temperature by month

Jan
Feb
Mar
Apr
May
Jun
65°
Jul
Aug
73°
Sep
60°
Oct
Nov
Dec

Typical surface water temperature by month, from 9 field readings (20222022) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Three Island Lake warm enough to swim?

At its summer peak (~69°F): Cool

Brisk but swimmable for short dips — most people acclimate after the first few minutes.

Want more than temperature? Three Island Lake scored A on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.

Where to stay near Three Island Lake

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Frequently asked questions

What is the water temperature of Three Island Lake?

Three Island Lake has a typical summer surface temperature of about 69°F. It is usually warmest in August (around 73°F) and coldest in September (around 60°F). These are typical values by month from 9 EPA Water Quality Portal field readings (2022–2022), not a live reading.

When is Three Island Lake warmest?

Surface water at Three Island Lake is typically warmest in August, reaching about 73°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 Three Island Lake warm enough to swim?

At its typical summer peak of about 69°F, Three Island Lake rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.

Where does this Three Island 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 — 9 readings from 1 monitoring station between 2022 and 2022. 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.