Ellis Lake Water Temperature
Ellis Lake in Lucas County, Iowa averages about 84°F at the surface in summer — warmest in Jul (~84°F) and coldest in May (~71°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 9 field readings (2018–2022) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Ellis Lake warm enough to swim?
Very comfortable for swimming. Warm surface water can also favor blue-green algae in nutrient-rich lakes, so check for advisories before you go in.
Want more than temperature? Ellis Lake scored F on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.
Water temperatures at nearby Iowa lakes
Summer average ~83°F
Summer average ~81°F
Summer average ~78°F
Summer average ~79°F
Summer average ~76°F
Summer average ~79°F
Explore water temperatures
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Frequently asked questions
What is the water temperature of Ellis Lake?
Ellis Lake has a typical summer surface temperature of about 84°F. It is usually warmest in July (around 84°F) and coldest in May (around 71°F). These are typical values by month from 9 EPA Water Quality Portal field readings (2018–2022), not a live reading.
When is Ellis Lake warmest?
Surface water at Ellis Lake is typically warmest in July, reaching about 84°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 Ellis Lake warm enough to swim?
At its typical summer peak of about 84°F, Ellis Lake rates as "warm" for swimming. Very comfortable for swimming. Warm surface water can also favor blue-green algae in nutrient-rich lakes, so check for advisories before you go in.
Where does this Ellis 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 — 9 readings from 1 monitoring station between 2018 and 2022. 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.