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LakeQuality

Upper Prior Lake Water Temperature

Upper Prior Lake in Scott County, Minnesota averages about 64°F at the surface in summer — warmest in Aug (~66°F) and coldest in Jan (~37°F). These are typical values by month, not a live reading.

Typical in July
65°F
Cool
Summer average
64°F
Warmest (Aug)
66°F
Coldest (Jan)
37°F

Typical water temperature by month

Jan
37°
Feb
Mar
Apr
47°
May
54°
Jun
61°
Jul
65°
Aug
66°
Sep
63°
Oct
58°
Nov
Dec

Typical surface water temperature by month, from 1,662 field readings (20102025) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Upper Prior Lake warm enough to swim?

At its summer peak (~64°F): Cool

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

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

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Frequently asked questions

What is the water temperature of Upper Prior Lake?

Upper Prior Lake has a typical summer surface temperature of about 64°F. It is usually warmest in August (around 66°F) and coldest in January (around 37°F). These are typical values by month from 1,662 EPA Water Quality Portal field readings (2010–2025), not a live reading.

When is Upper Prior Lake warmest?

Surface water at Upper Prior Lake is typically warmest in August, 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 Upper Prior Lake warm enough to swim?

At its typical summer peak of about 64°F, Upper Prior Lake rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.

Where does this Upper Prior 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 — 1,662 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.