Thunder Lake
Thunder Lake in Oneida County, Wisconsin has a water quality grade of C (Fair). Water clarity: 2.5 ft visibility. Phosphorus: 32.3 µg/L. Maximum depth: 12 ft. Surface area: 182 acres.
Wisconsin DNR rates Panfish as abundant on Thunder Lake. DNR survey details →
- Clarity
- 2.5 ft
- Typical in August
- 79°F
- Max depth
- 12 ft
- Area
- 182 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
Next lake in Oneida County
Swipe left or right on this bar to open the next or previous lake.
Thunder Lake is a 182-acre productive, nutrient-rich eutrophic lake in Oneida County, Wisconsin with a maximum depth of 12 feet. Water quality is graded C based on 1 sampling years through 2026. Overall water quality is declining over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass. Compared to the 66 other monitored lakes in Oneida County, Thunder Lake ranks #59 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-29. Grade methodology: LakeQuality methodology.
Watch Thunder Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyModerate
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 2.5 ft of visibility. Phosphorus level: 32.3 µg/L. Trophic State Index: 59.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.5 ft | Not graded |
| Phosphorus | 32.3 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 59 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Thunder Lake
Compare lakeside cabins, hotels, and vacation rentals near Thunder Lake in Oneida 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 Thunder 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
Thunder Lake typically sits around 79°F at the surface in August. Summer average is about 77°F. Usually warmest in Jul (about 81°F) and coldest in Jun (about 72°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 10 field readings (2024–2025) via the EPA Water Quality Portal. See the full Thunder Lake water temperature breakdown →
Wisconsin DNR rates Panfish as abundant on Thunder Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Thunder Lake C from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is declining. 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 2014. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Thunder Lake covering fish populations, stocking, water quality, and management. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2023Thunder Lake fisheries survey, 2023Fisheries Survey · WI DNR · 2023 (PDF)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 12 ft |
| Surface Area | 182 acres |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Thunder Lake
Water Quality Trend: ↓ Declining
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.076 m/yr | 7 |
| Phosphorus | ↓ Declining | +1.2 µg/L/yr | 4 |
County Ranking
Ranked #59 of 67 lakes in Oneida County
Nearby Lakes With Higher Grades
Thunder Lake holds Grade C. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Oneida County
Frequently asked questions about Thunder Lake
Where is Thunder Lake?
- Thunder Lake is a lake in Oneida County, Wisconsin. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Thunder Lake?
- Thunder Lake in Oneida County, Wisconsin has a water quality grade of C (Fair). Water clarity: 2.5 ft visibility. Phosphorus: 32.3 µg/L. Maximum depth: 12 ft. Surface area: 182 acres.
Is Thunder Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Thunder Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
What is the water temperature of Thunder Lake?
- Thunder Lake typically sits around 79°F at the surface in August, from 10 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Thunder Lake?
- Thunder Lake has a maximum depth of 12 feet. The lake covers 182 acres.
What fish are in Thunder Lake?
- Fish species found in Thunder Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Thunder Lake is located in Oneida County, Wisconsin.
What did the DNR fisheries survey find at Thunder Lake?
- Wisconsin DNR rates Panfish as abundant on Thunder Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Thunder Lake C from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Explore Thunder Lake across LakeQuality
Fish species and top-graded lakes across Wisconsin
Fish species and best lakes in Oneida County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Northwoods Wisconsin area
Top lakes and where to stay in the Minocqua Chain area
Where to stay at Wisconsin's top lakes, each with its grade
Lakes in the Wisconsin River Watershed, ranked by water quality
High nutrients, frequent algae, reduced clarity
Wisconsin's cleanest and most-polluted lakes, ranked
More Wisconsin Lake Rankings
Other Grade C Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Where this data comes from
37 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_WQX37 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