Saint Mary'S River Offshore Lake Water Temperature
Saint Mary'S River Offshore Lake in Chippewa County, Michigan averages about 59°F at the surface in summer — warmest in Aug (~67°F) and coldest in May (~44°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 212 field readings (2010–2025) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Saint Mary'S River Offshore Lake warm enough to swim?
Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Want more than temperature? Saint Mary'S River Offshore Lake scored A on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.
Water temperatures at nearby Michigan lakes
Summer average ~60°F
Summer average ~68°F
Summer average ~66°F
Summer average ~71°F
Summer average ~61°F
Summer average ~70°F
Explore water temperatures
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Frequently asked questions
What is the water temperature of Saint Mary'S River Offshore Lake?
Saint Mary'S River Offshore Lake has a typical summer surface temperature of about 59°F. It is usually warmest in August (around 67°F) and coldest in May (around 44°F). These are typical values by month from 212 EPA Water Quality Portal field readings (2010–2025), not a live reading.
When is Saint Mary'S River Offshore Lake warmest?
Surface water at Saint Mary'S River Offshore Lake is typically warmest in August, reaching about 67°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 Saint Mary'S River Offshore Lake warm enough to swim?
At its typical summer peak of about 59°F, Saint Mary'S River Offshore Lake rates as "cold" for swimming. Wetsuit territory. Brief exposure is tolerable but prolonged swimming without protection risks hypothermia.
Where does this Saint Mary'S River Offshore 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 — 212 readings from 1 monitoring station between 2010 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.