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LakeQuality

Johnson Lake Water Temperature

Johnson Lake in Becker County, Minnesota averages about 66°F at the surface in summer — warmest in Jul (~69°F) and coldest in May (~60°F). These are typical values by month, not a live reading.

Typical in July
69°F
Cool
Summer average
66°F
Warmest (Jul)
69°F
Coldest (May)
60°F

Typical water temperature by month

Jan
Feb
Mar
Apr
May
60°
Jun
63°
Jul
69°
Aug
67°
Sep
63°
Oct
Nov
Dec

Typical surface water temperature by month, from 161 field readings (20162024) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Johnson Lake warm enough to swim?

At its summer peak (~66°F): Cool

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

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

Where to stay near Johnson Lake

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Frequently asked questions

What is the water temperature of Johnson Lake?

Johnson Lake has a typical summer surface temperature of about 66°F. It is usually warmest in July (around 69°F) and coldest in May (around 60°F). These are typical values by month from 161 EPA Water Quality Portal field readings (2016–2024), not a live reading.

When is Johnson Lake warmest?

Surface water at Johnson Lake is typically warmest in July, reaching about 69°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 Johnson Lake warm enough to swim?

At its typical summer peak of about 66°F, Johnson Lake rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.

Where does this Johnson 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 — 161 readings from 1 monitoring station between 2016 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.