Castle Rock Dam Lake Water Temperature
Castle Rock Dam Lake in Hettinger County, North Dakota averages about 63°F at the surface in summer — warmest in Aug (~63°F) and coldest in Oct (~49°F). These are typical values by month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 12 field readings (2023–2023) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Castle Rock Dam Lake warm enough to swim?
Brisk but swimmable for short dips — most people acclimate after the first few minutes.
Want more than temperature? Castle Rock Dam Lake scored D on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.
Water temperatures at nearby North Dakota lakes
Summer average ~67°F
Summer average ~66°F
Summer average ~62°F
Summer average ~59°F
Summer average ~72°F
Summer average ~67°F
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Frequently asked questions
What is the water temperature of Castle Rock Dam Lake?
Castle Rock Dam Lake has a typical summer surface temperature of about 63°F. It is usually warmest in August (around 63°F) and coldest in October (around 49°F). These are typical values by month from 12 EPA Water Quality Portal field readings (2023–2023), not a live reading.
When is Castle Rock Dam Lake warmest?
Surface water at Castle Rock Dam Lake is typically warmest in August, reaching about 63°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 Castle Rock Dam Lake warm enough to swim?
At its typical summer peak of about 63°F, Castle Rock Dam Lake rates as "cool" for swimming. Brisk but swimmable for short dips — most people acclimate after the first few minutes.
Where does this Castle Rock Dam 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 — 12 readings from 1 monitoring station between 2023 and 2023. 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.