Milwaukee Harbor Estuary Lake Water Temperature
Milwaukee Harbor Estuary Lake in Milwaukee County, Wisconsin averages about 72°F at the surface in summer — warmest in Aug (~75°F) and coldest in Mar (~45°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 81 field readings (2024–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Milwaukee Harbor Estuary Lake warm enough to swim?
Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Want more than temperature? Milwaukee Harbor Estuary Lake scored D on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.
Water temperatures at nearby Wisconsin lakes
Summer average ~66°F
Summer average ~65°F
Summer average ~62°F
Summer average ~63°F
Summer average ~75°F
Summer average ~76°F
Explore water temperatures
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Frequently asked questions
What is the water temperature of Milwaukee Harbor Estuary Lake?
Milwaukee Harbor Estuary Lake has a typical summer surface temperature of about 72°F. It is usually warmest in August (around 75°F) and coldest in March (around 45°F). These are typical values by month from 81 EPA Water Quality Portal field readings (2024–2025), not a live reading.
When is Milwaukee Harbor Estuary Lake warmest?
Surface water at Milwaukee Harbor Estuary Lake is typically warmest in August, reaching about 75°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 Milwaukee Harbor Estuary Lake warm enough to swim?
At its typical summer peak of about 72°F, Milwaukee Harbor Estuary Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Where does this Milwaukee Harbor Estuary 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 — 81 readings from 1 monitoring station between 2024 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.