Bug Lake is a lake in Forest County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.

Is Bug Lake safe to swim in?

Based on E. coli testing, Bug Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 12 samples across 5 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Bug Lake is safe to swim in today is a call for Wisconsin's water agency and the county health department; check their current beach advisories before you swim.

What is the water temperature of Bug Lake?

Bug Lake typically sits around 50°F at the surface in October, from 160 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

Can I fish at Bug Lake?

Public access to Bug Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.

Bug Lake

Forest County, WisconsinView map Directions

Wisconsin DNR publishes the water-quality measurements for Bug Lake. Here is what has been measured.

Phosphorus

9.5 µg/L

Less phosphorus than most

Measured by Wisconsin DNR

Chlorophyll-a

1 µg/L

Less algae than most

Measured by Wisconsin DNR

Water temp

~50°F

Typical for Oct · EPA WQP

Type

Oligotrophic

Trophic class

Trend

Stable

6 years of samples

Oligotrophic
Public access

See the measurements Directions Where to stay

Bug Lake in Forest County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 1 µg/L.

Loading map…

Bug Lake is a cold, clear oligotrophic lake in Forest County, Wisconsin. Phosphorus level is declining over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 22 other monitored lakes in Forest County, Bug Lake ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-11-19. Methodology: how these readings are compared.

Swimming conditions

Readings only

Bacteria tested: low

Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Bacteria testing record

from E. coli testing · 12 samples, 5 seasons

Based on E. coli testing, Bug Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 12 samples across 5 seasons.

This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Wisconsin’s current beach and health-department advisories before swimming.

Whether Bug Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

Compare swimming lakes near Rhinelander →

Get alerts for Bug Lake →

Water quality measurements for Bug Lake

These are the measurements Wisconsin DNR publishes for Bug Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

No clarity data. Phosphorus 9.5 µg/L. Chlorophyll-a 1 µg/L. TSI 34.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)		No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	9.5µg/L	Good GoodFairPoor
Chlorophyll-a (algae)	1µg/L	Good GoodFairPoor
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.	34	Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic

Low nutrients, clear water. No reading is a swimming clearance.

Ask about Bug Lake

Answers come straight from the public measurements and survey records on this page.

Water Temperature

Bug Lake typically sits around 50°F at the surface in October. Summer average is about 52°F. Usually warmest in Aug (about 54°F) and coldest in Nov (about 41°F). These are typical values by month — not a live reading.

Jan

Feb

Mar

42°

Apr

47°

May

49°

Jun

53°

Jul

54°

Aug

54°

Sep

50°

Oct

41°

Nov

Dec

Column height runs from this lake’s coldest month (41°F) to its warmest (54°F).

Typical surface water temperature by month, from 160 field readings (2024–2025) via the EPA Water Quality Portal. See the full Bug Lake water temperature breakdown →

Stays via Stay22

Stays near Bug Lake

Compare lakeside cabins, hotels, and vacation rentals near Bug 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 Bug Lake

Prices for Oct 9–11, 4 adults. Change dates on the map below.

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 →

Follow Bug Lake’s readings

Email me when new measurements post for this lake. Updates stay free.

Or email

Fishing Bug Lake

→ Bug Lake fishing regulations (limits, seasons, special rules)

Water Quality Trend: Stable

Based on 6 years of monitoring (2020–2025).

Phosphorus
Worsening
+0.49 µg/L/yr6 years
Chlorophyll-a
Improving
-0.15 µg/L/yr6 years

See year-by-year chart →

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Bug Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.

Crandon Recirculating Sand Filter/Stone Lake Wwtp
Crandon · 1.5 mi away · NPDES WI0058424
Recent violation

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

Nearby Lakes in Forest County

Devil'S LakeMesotrophic—View →Devils Lake—View →Wabikon Lake—View →Riley Lake—View →Lake Lucerne18.7 ft clear · Oligotrophic—View →Peshtigo Lake—View →

Frequently asked questions about Bug Lake

Where is Bug Lake?: Bug Lake is a lake in Forest County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Bug Lake?: Bug Lake in Forest County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 1 µg/L.
Is Bug Lake safe to swim in?: Based on E. coli testing, Bug Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 12 samples across 5 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Bug Lake is safe to swim in today is a call for Wisconsin's water agency and the county health department; check their current beach advisories before you swim.
What is the water temperature of Bug Lake?: Bug Lake typically sits around 50°F at the surface in October, from 160 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
Can I fish at Bug Lake?: Public access to Bug Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.

Explore Bug Lake across LakeQuality

Wisconsin Fishing Guide

Fish species and the cleanest lakes across Wisconsin

Forest County Fishing

Fish species and best lakes in Forest County

Lake Fishing Forecast

Species activity outlook by water temperature and season

Northwoods Wisconsin

Top lakes and where to stay in the Northwoods Wisconsin area

Wisconsin Lake Trips

Where to stay at Wisconsin's top lakes, each with its readings

Wolf River Watershed

Lakes in the Wolf River Watershed, ranked by water quality

The State of Wisconsin's Lakes

Wisconsin's cleanest lakes, ranked on agency measurements

More lakes in Wisconsin

Clearest lakes in Wisconsin

Ranked by Secchi water clarity

All Wisconsin lakes

Every Wisconsin lake with its Wisconsin DNR measurements

Lake water quality by country

Official ratings and named-lake measurements

Other Lakes in Wisconsin

King Lake

Marinette County · Measured

Big Lake

Shawano County · 8 ft

Koonz Lake

Shawano County · 10.8 ft

Bealeau Lake

Shawano County · 11.5 ft

Malone Lake

Shawano County · 13.5 ft

Sams Lake

Shawano County · 11 ft

Oligotrophic Lakes in Wisconsin

Big Twin Lake Perch Lake Explosion Lake Rose Lake

Where this data comes from

84 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

Forest County Potawatomi Community (Tribal)FCPOTAWATOMI_WQX84 samples · 2020–2025

Analytical methods

4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
4500 P F ~ Phosphorus in Water by Colorimetry Automated Ascorbic Acid Method
10200 H ~ Chlorophyll a-b-c Determination

Monitoring station identifiers (1)

FCPOTAWATOMI_WQX-BUG

EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.