Lake of the Woods
Lake of the Woods in Lake of the Woods County, Minnesota has a water quality grade of C (Fair). Water clarity: 3.3 ft visibility. Phosphorus: 35 µg/L. Chlorophyll-a (algae): 5.7 µg/L.
- Clarity
- 3.3 ft
- Typical in August
- 68°F
- Mean depth
- ~35 ft est.
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- May 5
Next lake in Lake of the Woods County
Lake of the Woods is a productive, nutrient-rich eutrophic lake in Lake of the Woods County, Minnesota with an estimated average depth of about 35 feet. Water quality is graded C based on 2 sampling years through 2023. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 9 other monitored lakes in Lake of the Woods County, Lake of the Woods ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-09-25. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Very murky, less than 3.3 ft of visibility. Phosphorus level: 35 µg/L. Chlorophyll-a: 5.7 µg/L. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.3 ft | Not graded |
| Phosphorus | 35 µg/L | Fair |
| Chlorophyll-a (Algae) | 5.7 µg/L | Good |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Lake of the Woods
Compare lakeside cabins, hotels, and vacation rentals near Lake of the Woods in Lake of the Woods County, Minnesota — 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 Lake of the Woods
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Water Temperature
Lake of the Woods typically sits around 68°F at the surface in August. Summer average is about 68°F. Usually warmest in Jul (about 72°F) and coldest in Mar (about 34°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 142 field readings (2010–2024) via the EPA Water Quality Portal. See the full Lake of the Woods water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~35 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Lake of the Woods.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Lake of the Woods
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Lake of the Woods. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Public Water Access Sites — Lake of the Woods (Main)Public Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +2.25 m/yr | 2 |
| Phosphorus | ↑ Improving | -4 µg/L/yr | 2 |
| Chlorophyll-a | ↓ Declining | +1.3 µg/L/yr | 2 |
Ice Season
Historical ice data from Minnesota DNR (6 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 1976-04-26 (1976) | 1996-05-19 (1996) |
| Ice-In | 1986-11-11 (1986) | 1988-11-17 (1988) |
Most recent ice-out: 1997-05-06
County Ranking
Ranked #5 of 10 lakes in Lake of the Woods County
Nearby Lakes in Lake of the Woods County
Frequently asked questions about Lake of the Woods
What is the water quality grade for Lake of the Woods?
- Lake of the Woods in Lake of the Woods County, Minnesota has a water quality grade of C (Fair). Water clarity: 3.3 ft visibility. Phosphorus: 35 µg/L. Chlorophyll-a (algae): 5.7 µg/L.
Is Lake of the Woods safe to swim in?
- Generally safe for swimming, moderate water quality. Lake of the Woods has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 5.7 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Lake of the Woods?
- Lake of the Woods typically sits around 68°F at the surface in August, from 142 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Lake of the Woods?
- No published bathymetric survey covers Lake of the Woods, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 35 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
When does Lake of the Woods thaw?
- Lake of the Woods typically has ice-out around May 5.
Explore Lake of the Woods across LakeGrade
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Where this data comes from
28 measurements from 1 monitoring station, 2022–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA28 samples · 2022–2023
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity, Nephelometric Method
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)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate