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: 4.8 ft visibility. Phosphorus: 26 µg/L. Chlorophyll-a (algae): 9.9 µg/L.
- Clarity
- 4.8 ft
- Type
- Eutrophic
- Trend
- ↓ Declining
- 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. Water quality is graded C based on 2 sampling years through 2021. Overall water quality is declining 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 #3 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-09-21. Grade methodology: LakeGrade methodology.
Watch Lake of the Woods water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
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)
Murky, only visible to about 4.8 ft. Phosphorus level: 26 µg/L. Chlorophyll-a: 9.9 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.8 ft | Not graded |
| Phosphorus | 26 µg/L | Fair |
| Chlorophyll-a (Algae) | 9.9 µg/L | Fair |
| Trophic State Index (TSI) | 53 | 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
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 Minnesota’s top lakes →
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: ↓ Declining
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.246 m/yr | 3 |
| Phosphorus | → Stable | -0.25 µg/L/yr | 3 |
| Chlorophyll-a | → Stable | -0.11 µg/L/yr | 3 |
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 #3 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: 4.8 ft visibility. Phosphorus: 26 µg/L. Chlorophyll-a (algae): 9.9 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 9.9 µg/L. Always check local health department advisories before swimming.
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
Fish species and top-graded lakes across Minnesota
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Rainy Lake Watershed, ranked by water quality
High nutrients, frequent algae, reduced clarity
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Lake of the Woods
Other Grade C Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
17 measurements from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Red Lake DNR
REDLAKE_WQX17 samples · 2021
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity by Nephelometry
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)
Ice data from Minnesota DNR Climate