Harpt Lake
Manitowoc County, Wisconsin · WBIC 84600
The DNR lists this lake's watershed (East Twin River-Frontal Lake Michigan) as suspect or infected with VHS, a fish virus. The listing covers the watershed, not a test of this lake. About VHS
Size
31 acres
Max depth
54 ft
DNR lake type
Complex, Warm, dark water color
Water clarity
5 ft
Moderate, measured Aug 2026
A warm-water lake type: the DNR groups it with lakes that warm up through summer. This describes the lake type in general, not this lake in particular.
Outline
Numbered dots are boat landings; tap one for directions. The list below has the same numbers. Drawn from the DNR's 24K hydrography (surveyed 1978), so the shape is approximate and a landing can sit a little off the shore. Open the DNR lake map.
Water clarity
5 ft Secchi depthModerate
Last measured Aug 17, 2026. 212 readings on record, 1994 to 2026.
Typical summer clarity (June to September): 6.9 ft, moderate, from 67 readings (2012 to 2026).
Secchi depth is how far down a white disk stays visible. A bigger number means clearer water. Clear means a Secchi depth of 10 feet or more, moderate 5 to 10 feet, low under 5 feet.
Wisconsin DNR water monitoring (volunteer and staff), via the Water Quality Portal; station HARPT LAKE - DEEP HOLE. Checked Oct 23, 2026.
Water temperature
Last measured Jul 22, 2025, too long ago to show as the current temperature.
A typical year Modeled estimate
- Ice goes outabout Mar 31 (Mar 23 to Apr 6)
- Surface reaches 48°Fabout Apr 18 (Apr 10 to Apr 21)
- Surface reaches 64°Fabout May 21 (May 10 to May 27)
- June surface71°F, usually 71 to 73°F
- July surface79°F, usually 77 to 80°F
- August surface77°F, usually 75 to 79°F
Forms a warm top layer around Apr 15, lasting about 223 days.
A computer model of this lake's typical weather and water, built from 15 years, 2005 to 2019. Ranges show the middle half of years. The model was not calibrated against measured temperatures for this lake. It is an estimate, not a measurement.
Measured: Wisconsin DNR via the Water Quality Portal (checked Oct 23, 2026). Modeled: U.S. Geological Survey lake temperature data release (doi:10.5066/P9CA6XP8).
Today at the lake
Forecast: National Weather Service (no endorsement implied). Sunrise, sunset and moon phase are calculated. The moon phase can be a day off.
Boat landings
- 1Harpt Lake Boat RampBoat ramp · Concrete surface · County
Directions
Wisconsin DNR public boat access sites. Checked Oct 23, 2026.
More lakes in Manitowoc County
- Tuma Lake0.8 miles away
- Mott Lake0.9 miles away
- Kellners Lake6.9 miles away
- Shoto Lake9.1 miles away
- Hempton Lake12 miles away
- Schisel Lake13 miles away
Where this comes from
- Size, depth and lake typeWisconsin DNR lake classifications, checked Oct 23, 2026
- OutlineWisconsin DNR 24K hydrography, checked Oct 23, 2026
- Boat landingsWisconsin DNR public boat access sites, checked Oct 23, 2026
- Water clarityWisconsin DNR water monitoring, via the Water Quality Portal, checked Oct 23, 2026
- Typical-year temperatureU.S. Geological Survey lake temperature model (modeled estimate), checked Oct 23, 2026
- VHS statusWisconsin DNR VHS status by watershed, checked Oct 24, 2026
- Depth map linkWisconsin DNR lake maps list, checked Oct 24, 2026
See data sources for what each source covers, and about for how the numbers are matched to lakes.
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