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LakeQuality

Windfall Lake

B
Grade B — Good
Good · #11 of 23 lakes in the county · 10 ft clear · Mesotrophic · 53 acres
Mesotrophic

Windfall Lake in Forest County, Wisconsin has a water quality grade of B (Good). Water clarity: 10 ft visibility. Phosphorus: 21.2 µg/L. Maximum depth: 25 ft. Surface area: 53 acres.

Wisconsin DNR rates Panfish as abundant on Windfall Lake. DNR survey details →

Clarity
10 ft
Typical in August
71°F
Max depth
25 ft
Area
53 acres
Type
Mesotrophic
Trend
Stable
Public access
Yes

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Windfall Lake is a 53-acre mesotrophic lake in Forest County, Wisconsin with a maximum depth of 25 feet. Water quality is graded B based on 1 sampling years through 2026. Water clarity is improving over recent sampling years. The lake supports 4 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 3 public boat landings. Compared to the 22 other monitored lakes in Forest County, Windfall Lake ranks #11 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-12. Grade methodology: LakeQuality methodology.

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Swimming Safety

Grade only

Low 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

Compare the safest swimming lakes near Rhinelander

Get alerts for Windfall Lake

Water Quality Grade: B (Good)

Good clarity, visible to about 10 ft. Phosphorus level: 21.2 µg/L. Trophic State Index: 46.

MetricValueGrade
Water Clarity (Secchi Depth)10 ftNot graded
Phosphorus21.2 µg/LGood
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)46Mesotrophic

Moderate nutrients, good water quality

Where to stay near Windfall Lake

Compare lakeside cabins, hotels, and vacation rentals near Windfall Lake in Forest 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 Windfall Lake

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 →

Water Temperature

Windfall Lake typically sits around 71°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 79°F) and coldest in May (about 62°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
62°
Jun
71°
Jul
79°
Aug
71°
Sep
Oct
Nov
Dec

Typical surface water temperature by month, from 25 field readings (20242025) via the EPA Water Quality Portal. See the full Windfall Lake water temperature breakdown →

DNR fisheries survey

Wisconsin DNR rates Panfish as abundant on Windfall Lake.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Windfall Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is stable. 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 1994. 4 stations on file (most recent sample 2025).

Fish Species (DNR-rated)

Panfish(Abundant)Largemouth Bass(Common)Northern Pike(Common)Musky(Present)

Lake Details

CharacteristicValue
Maximum Depth25 ft
Surface Area53 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
4 sq mi
Shoreline
1.5 mi
Elevation
1,516 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

3
Boat Landings
Yes
Public Access
1
Campgrounds
  • Windfall LakePublic
  • Ada Lake CampgroundPublic
  • Glade LakePublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Public campgrounds near Windfall Lake

  • Ada Lake2.8 km

Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Windfall Lake

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.25 m/yr7
Phosphorus Declining+2.78 µg/L/yr5
See year-by-year chart →

County Ranking

Ranked #11 of 23 lakes in Forest County

Nearby Lakes in Forest County

Frequently asked questions about Windfall Lake

Where is Windfall Lake?

Windfall Lake is a lake in Forest County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Windfall Lake?

Windfall Lake in Forest County, Wisconsin has a water quality grade of B (Good). Water clarity: 10 ft visibility. Phosphorus: 21.2 µg/L. Maximum depth: 25 ft. Surface area: 53 acres.

Is Windfall Lake safe to swim in?

Good for swimming, clear water with low algae levels. Windfall Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.

What is the water temperature of Windfall Lake?

Windfall Lake typically sits around 71°F at the surface in August, from 25 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Windfall Lake?

Windfall Lake has a maximum depth of 25 feet. The lake covers 53 acres.

What fish are in Windfall Lake?

Fish species found in Windfall Lake include Musky, Panfish, Largemouth Bass, Northern Pike. Windfall Lake is located in Forest County, Wisconsin.

What did the DNR fisheries survey find at Windfall Lake?

Wisconsin DNR rates Panfish as abundant on Windfall Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Windfall Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.

Are there boat ramps on Windfall Lake?

Windfall Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Windfall Lake, Ada Lake Campground, Glade Lake. Public access is listed as yes.

Are there campgrounds on Windfall Lake?

Windfall Lake has 1 public campground from USGS The National Map within 5 km, including Ada Lake. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.

Mesotrophic Lakes in Wisconsin

Where this data comes from

144 measurements from 2 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX144 samples · 2020–2026

Analytical methods

  • Phosphorus by Colorimetry
Monitoring station identifiers (2)

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

Public campgrounds from USGS The National Map Structures, within about 3 miles