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Niagara Dam Lake Water Temperature

Niagara Dam Lake in Grand Forks County, North Dakota typically sits around 60°F at the surface in September — warmest in Jul (~73°F) and coldest in Oct (~52°F). That is a typical value for the month, not a live reading.

Typical in September
60°F
Cool
Summer average
71°F
Warmest (Jul)
73°F
Coldest (Oct)
52°F

Typical water temperature by month

Jan
Feb
Mar
Apr
May
59°
Jun
68°
Jul
73°
Aug
Sep
60°
Oct
52°
Nov
Dec

Typical surface water temperature by month, from 15 field readings (20152025) via the EPA Water Quality Portal. Months with too few readings are left blank.

Is Niagara Dam Lake warm enough to swim?

At its summer peak (~71°F): Comfortable

Pleasant for swimming — the range most people find enjoyable without a wetsuit.

Want more than temperature? Niagara Dam Lake scored NR on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.

Where to stay near Niagara Dam Lake

Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Niagara Dam Lake — live availability and prices. Switch the map to Satellite to see the lake and how close each stay is to the water.

Top-rated places to stay near Niagara Dam Lake

Prices for Sep 11–13, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

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Frequently asked questions

What is the water temperature of Niagara Dam Lake?

Niagara Dam Lake typically sits around 60°F at the surface in September, from 15 EPA Water Quality Portal field readings (2015–2025). That is a typical value for the month, not a live reading.

When is Niagara Dam Lake warmest?

Surface water at Niagara Dam Lake is typically warmest in July, reaching about 73°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 Niagara Dam Lake warm enough to swim?

At its typical summer peak of about 71°F, Niagara Dam Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.

Where does this Niagara 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 — 15 readings from 1 monitoring station between 2015 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.