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LakeQuality

Upper Lake Water Temperature

Upper Lake in Ramsey County, Minnesota averages about 57°F at the surface in summer — warmest in Aug (~59°F) and coldest in Mar (~41°F). These are typical values by month, not a live reading.

Typical in July
57°F
Cold
Summer average
57°F
Warmest (Aug)
59°F
Coldest (Mar)
41°F

Typical water temperature by month

Jan
Feb
Mar
41°
Apr
43°
May
50°
Jun
55°
Jul
57°
Aug
59°
Sep
57°
Oct
54°
Nov
Dec

Typical surface water temperature by month, from 913 field readings (20112025) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Upper Lake warm enough to swim?

At its summer peak (~57°F): Cold

Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.

Want more than temperature? Upper Lake scored D 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 Lake?

Upper Lake has a typical summer surface temperature of about 57°F. It is usually warmest in August (around 59°F) and coldest in March (around 41°F). These are typical values by month from 913 EPA Water Quality Portal field readings (2011–2025), not a live reading.

When is Upper Lake warmest?

Surface water at Upper Lake is typically warmest in August, reaching about 59°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 Lake warm enough to swim?

At its typical summer peak of about 57°F, Upper Lake rates as "cold" for swimming. Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.

Where does this Upper 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 — 913 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.