Two Sisters Lake Water Temperature
Two Sisters Lake in Oneida County, Wisconsin averages about 71°F at the surface in summer — warmest in Jul (~74°F) and coldest in May (~53°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 24 field readings (2024–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Two Sisters Lake warm enough to swim?
Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Want more than temperature? Two Sisters Lake scored A 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 ~73°F
Summer average ~76°F
Summer average ~73°F
Summer average ~73°F
Summer average ~71°F
Summer average ~73°F
Explore water temperatures
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Frequently asked questions
What is the water temperature of Two Sisters Lake?
Two Sisters Lake has a typical summer surface temperature of about 71°F. It is usually warmest in July (around 74°F) and coldest in May (around 53°F). These are typical values by month from 24 EPA Water Quality Portal field readings (2024–2025), not a live reading.
When is Two Sisters Lake warmest?
Surface water at Two Sisters Lake is typically warmest in July, reaching about 74°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 Two Sisters Lake warm enough to swim?
At its typical summer peak of about 71°F, Two Sisters Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Where does this Two Sisters 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 — 24 readings from 2 monitoring stations 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.