Upper Nemahbin Lake
Waukesha County, Wisconsin · WBIC 827100
Size
283 acres
Max depth
61 ft
DNR lake type
Complex, Two Story
Water clarity
18 ft
Clear, measured Aug 2026
A deep lake type that can hold a cold layer below the warm surface in 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 1976), so the shape is approximate and a landing can sit a little off the shore. Open the DNR lake map.
Water clarity
18 ft Secchi depthClear
Last measured Aug 24, 2026. 202 readings on record, 1986 to 2026.
Typical summer clarity (June to September): 13 ft, clear, from 62 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 UPPER NEMAHBIN LAKE - DEEP HOLE. Checked Oct 23, 2026.
Water temperature
Last measured Aug 24, 2026, too long ago to show as the current temperature.
A typical year Modeled estimate
- Ice goes outabout Apr 7 (Mar 27 to Apr 10)
- Surface reaches 48°Fabout Apr 22 (Apr 13 to Apr 26)
- Surface reaches 64°Fabout May 13 (May 8 to May 23)
- June surface76°F, usually 75 to 77°F
- July surface82°F, usually 80 to 83°F
- August surface78°F, usually 76 to 80°F
Forms a warm top layer around Apr 21, lasting about 201 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 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.
Stocking history
- Walleyelast stocked 2024 (large fingerling and small fingerling); stocked in 8 years since 2010
- Rainbow Troutlast stocked 2023 (yearling); stocked in 2 years since 2010
- Northern Pikelast stocked 2017 (large fingerling); stocked in 6 years since 2010
Stocking shows what was added to the lake, not what is in it now.
Wisconsin DNR annual fish stocking summary. Checked Oct 23, 2026.
Fish recorded near this lake
- Black Crappie Pomoxis nigromaculatus2006; 1 record
- Bluegill Lepomis macrochirus1966 to 2006; 7 records
- Brook Trout Salvelinus fontinalis2006; 1 record
- Brown Trout Salmo trutta2006; 1 record
- Green Sunfish Lepomis cyanellus2006; 1 record
- Largemouth Bass Micropterus salmoides2000 to 2006; 7 records
- Longnose Gar Lepisosteus osseus2006; 1 record
- Northern Pike Esox lucius1966 to 2006; 3 records
- Pumpkinseed Lepomis gibbosus1966; 1 record
- Rainbow Trout Oncorhynchus mykiss1966 to 2006; 2 records
- Rock Bass Ambloplites rupestris1966 to 2006; 5 records
- Smallmouth Bass Micropterus dolomieu2000 to 2006; 7 records
- Walleye Sander vitreus2006; 4 records
- White Bass Morone chrysops2000; 1 record
- White Sucker Catostomus commersonii2006; 1 record
- Yellow Bullhead Ameiurus natalis1966; 1 record
- Yellow Perch Perca flavescens2006; 4 records
Recorded in open fish survey and museum records (GBIF). A record shows a fish was found near this lake in that year, not that it is there now, and says nothing about how many. Most coordinates are rounded to about 1 km, so a record is attached only when one lake is the clear match.
Open fish survey and museum records from GBIF; datasets are listed on the sources page. Checked Oct 23, 2026.
Boat landings
- 1Nemahbin Lakes Boat RampBoat ramp · Concrete Panels surface · County
Directions
Wisconsin DNR public boat access sites. Checked Oct 23, 2026.
More lakes in Waukesha County
- Lower Nashotah Lake0.7 miles away
- Applebecker Millpond0.7 miles away
- Lower Nemahbin Lake1.2 miles away
- Upper Nashotah Lake1.3 miles away
- Crooked Lake1.5 miles away
- Bowron Lake1.5 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
- Stocking historyWisconsin DNR annual fish stocking summary, checked Oct 23, 2026
- Regulations linkWisconsin DNR fishing regulations (linked, not restated), 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
- Fish recordedOpen fish survey and museum records, via GBIF, 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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