Loon Lake
Shawano County, Wisconsin327 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Loon Lake. Here is what has been measured.
- Eutrophic
- 2 aquatic invasives
- 22 ft max depth
- Public access
Loon Lake in Shawano County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5.5 ft visibility. Phosphorus: 20.8 µg/L. Maximum depth: 22 ft. Surface area: 327 acres.
Wisconsin DNR lists Panfish as common on Loon Lake. DNR survey details →
Loon Lake is a 327-acre productive, nutrient-rich eutrophic lake in Shawano County, Wisconsin with a maximum depth of 22 feet. Overall water quality is improving over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 20 other monitored lakes in Shawano County, Loon Lake ranks #11 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-28. Methodology: how these readings are compared.
Loon Lake covers about 330 acres in Shawano County. It has one public boat landing. Vrbo is where to look for cabins and lake homes around Loon Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Loon Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing4 species recorded
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Loon Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Loon Lake
These are the measurements Wisconsin DNR publishes for Loon Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5.5 ft. Phosphorus 20.8 µg/L. TSI 50.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 20.8µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 50 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Loon Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Loon Lake typically sits around 69°F at the surface in August. Summer average is about 72°F. Usually warmest in Jun (about 74°F) and coldest in May (about 61°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (61°F) to its warmest (74°F).
Typical surface water temperature by month, from 9 field readings (2024–2025) via the EPA Water Quality Portal. See the full Loon Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Loon Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (222,844 cells/mL) on June 6, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Wisconsin DNR lists Panfish as common on Loon Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Loon Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1990. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
22 ft
Surface area
327 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
4 sq mi
HydroLAKES / HydroSHEDS
Shoreline
2.8 mi
HydroLAKES / HydroSHEDS
Elevation
791 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Loon LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Loon Lake
Compare lakeside cabins, hotels, and vacation rentals near Loon Lake in Shawano County, Wisconsin — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Loon Lake
Prices for Oct 9–11, 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.
Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Follow Loon Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
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Fish Species
Click a species to see every lake where it is documented.
Fishing Loon Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: Improving
Based on 7 years of monitoring (2020–2026).
Water clarity
Improving7 years
Phosphorus
Improving-0.74 µg/L/yr7 years
Nearby Lakes in Shawano County
Frequently asked questions about Loon Lake
Where is Loon Lake?
- Loon Lake is a lake in Shawano County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Loon Lake?
- Loon Lake in Shawano County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5.5 ft visibility. Phosphorus: 20.8 µg/L. Maximum depth: 22 ft. Surface area: 327 acres.
Is Loon Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Loon Lake?
- Loon Lake typically sits around 69°F at the surface in August, from 9 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Loon Lake?
- Loon Lake has a maximum depth of 22 feet. The lake covers 327 acres.
What fish are in Loon Lake?
- Fish species found in Loon Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Loon Lake is located in Shawano County, Wisconsin.
What did the DNR fisheries survey find at Loon Lake?
- Wisconsin DNR lists Panfish as common on Loon Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Loon Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Does Loon Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Loon Lake (clouds, ice, or an off-season gap). The most recent reading was high (222,844 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Loon Lake?
- Loon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Loon Lake. Public access is listed as yes.
Can I fish at Loon Lake?
- Loon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.
Explore Loon Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Wisconsin
Fish species and best lakes in Shawano County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its readings
Lakes in the Wolf River Watershed, ranked by water quality
Wisconsin's cleanest lakes, ranked on agency measurements
More lakes in Wisconsin
Other Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Where this data comes from
47 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX47 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory