Armour Lake
Armour Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 10.5 ft visibility. Phosphorus: 12.3 µg/L. Maximum depth: 56 ft. Surface area: 328 acres.
Wisconsin DNR lists Panfish as common on Armour Lake. DNR survey details →
- Clarity
- 10.5 ft
- Typical in August
- 72°F
- Max depth
- 56 ft
- Area
- 328 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
Next lake in Vilas County
Swipe left or right on this bar to open the next or previous lake.
Armour Lake is a 328-acre mesotrophic lake in Vilas County, Wisconsin with a maximum depth of 56 feet. Water quality is graded B based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass. Compared to the 102 other monitored lakes in Vilas County, Armour Lake ranks #30 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-10-27. Grade methodology: LakeQuality methodology.
Watch Armour Lake 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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Good clarity, visible to about 10.5 ft. Phosphorus level: 12.3 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.5 ft | Not graded |
| Phosphorus | 12.3 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Armour Lake
Compare lakeside cabins, hotels, and vacation rentals near Armour Lake in Vilas 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 Armour 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
Armour Lake typically sits around 72°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 79°F) and coldest in Oct (about 53°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 10 field readings (2025–2025) via the EPA Water Quality Portal. See the full Armour Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Armour Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (524,807 cells/mL) on November 8, 2025.
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 Armour Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Armour Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 6 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 1998. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 56 ft |
| Surface Area | 328 acres |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Armour Lake
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.086 m/yr | 6 |
| Phosphorus | ↑ Improving | -0.47 µg/L/yr | 5 |
EPA Impairment Status
Armour Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10007528 · Official waterbody report · Matched by proximity (2.38 km)
County Ranking
Ranked #30 of 103 lakes in Vilas County
Nearby Lakes in Vilas County
Frequently asked questions about Armour Lake
Where is Armour Lake?
- Armour Lake is a lake in Vilas County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Armour Lake?
- Armour Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 10.5 ft visibility. Phosphorus: 12.3 µg/L. Maximum depth: 56 ft. Surface area: 328 acres.
Is Armour Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Armour Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
What is the water temperature of Armour Lake?
- Armour Lake typically sits around 72°F at the surface in August, from 10 EPA Water Quality Portal field readings (2025–2025). That is a typical value for the month, not a live reading.
How deep is Armour Lake?
- Armour Lake has a maximum depth of 56 feet. The lake covers 328 acres.
What fish are in Armour Lake?
- Fish species found in Armour Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Armour Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Armour Lake?
- Wisconsin DNR lists Panfish as common on Armour Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Armour Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Does Armour Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Armour Lake (clouds, ice, or an off-season gap). The most recent reading was high (524,807 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Explore Armour Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Wisconsin
Fish species and best lakes in Vilas County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Northwoods Wisconsin area
Where to stay at Wisconsin's top lakes, each with its grade
Lakes in the Wisconsin River Watershed, ranked by water quality
Moderate nutrients, good water quality
Wisconsin's cleanest and most-polluted lakes, ranked
More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
Where this data comes from
29 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX29 samples · 2020–2025
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes