Loon Lake
Loon Lake in Shawano County, Wisconsin has a water quality grade of B (Good). Water clarity: 5.5 ft visibility. Phosphorus: 20.8 µg/L. Maximum depth: 22 ft. Surface area: 327 acres.
- Clarity
- 5.5 ft
- Typical in August
- 69°F
- Max depth
- 22 ft
- Area
- 327 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Shawano County
Loon Lake is a 327-acre productive, nutrient-rich eutrophic lake in Shawano County, Wisconsin with a maximum depth of 22 feet. Water quality is graded B based on 1 sampling years through 2026. 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 2 public boat landings. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLow algae
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Murky, only visible to about 5.5 ft. Phosphorus level: 20.8 µg/L. Trophic State Index: 50.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.5 ft | Not graded |
| Phosphorus | 20.8 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 50 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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
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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.
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 ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 22 ft |
| Surface Area | 327 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Shawano Lake County ParkPublic
- Loon LakePublic
Fish Species
Click a species to see every graded 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.
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)
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.245 m/yr | 7 |
| Phosphorus | ↑ Improving | -0.74 µg/L/yr | 7 |
County Ranking
Ranked #11 of 21 lakes in Shawano County
Nearby Lakes in Shawano County
Frequently asked questions about Loon Lake
What is the water quality grade for Loon Lake?
- Loon Lake in Shawano County, Wisconsin has a water quality grade of B (Good). 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?
- Good for swimming, clear water with low algae levels. Loon Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
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.
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 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Shawano Lake County Park, Loon Lake. Public access is listed as yes.
Explore Loon Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Shawano County
Species activity outlook by water temperature and season
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Other Grade B Lakes in Wisconsin
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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)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated 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