Skip to content
RADON411

Locations and reports

Radon Levels in Washburn County, Wisconsin

EPA puts Washburn County in Zone 2, its middle radon zone, and high results are common there: 44.9% of the 49 radon tests reported to CDC (2023) came back at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    44.9%

    9.2 pts above WI

    Washburn
    44.9%
    Wisconsin
    35.7%

    49 tests, 2023

  • Median result

    3.1pCi/L

    Below action level

    Washburn
    3.1 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    49

    59th of 69 by tests

    Washburn
    49
    Dane
    2,887

    Reported to CDC before any fix, 2023

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Wisconsin

    17 of 69

    Top quarter

    Washburn
    44.9%
    Langlade
    65.8%

    By share, of 69 with 30+ tests

Read a result for Washburn County

Starts at Washburn County's median, 3.1 pCi/L

3.1pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 3.1 pCi/L

Between 2 and 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Washburn County's median reported result, 2023.

Interpret this readingWhat a fix costs

The data

Washburn County, At a glance

Washburn County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Washburn County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Washburn County, 2023

Share of reported tests at or above 4 pCi/L, by year, Washburn County
Share of reported tests at or above 4 pCi/L, by year, Washburn County
YearShare of reported tests at or above 4 pCi/L
201435.5%
201545.7%
201629.0%
201738.7%
201939.4%
202027.6%
202128.2%
202232.4%
202344.9%

2023: 44.9%. Across these years the share ran from 27.6% to 45.7%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 49 tests reported to CDC for Washburn County over 2023, many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.

Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Washburn County, Compared

Washburn County radon figures, compared

Calculated by Radon411

In Washburn County, about 4 in 10 reported tests in 2023 (22 of 49) were at or above EPA's action level. Against the national pool of 33.4%, the gap is 11.5 points higher. Across 72 Wisconsin counties pooled together, 35.7% of tests reached that level, so Washburn County runs 9.2 points above its state.

Of 6 neighbours with a figure, none reported a larger share at or above 4 pCi/L; the spread is 5.7% (Bayfield County) to 42.6% (Sawyer County). By share, Washburn County is 17th of 69 Wisconsin counties with 30 or more tests for the same period.

Year by year, 2014 opened at 35.5% and 2023 closed at 44.9% (up 9.4 points), with 2015 the high at 45.7%. Half the tests came in under 3.1 pCi/L and half over it; the single highest reached 16.0 pCi/L. Below the action level, 16 tests (32.7%) came in under 2 pCi/L, against 41.4% statewide, and 11 tests (22.4%) fell between 2 and 4, against 23.0% statewide.

Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 44.9% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential.

The busiest year on file was 2023, with 49 tests reported; the quietest, 2020, had 29.

Share of reported tests at or above 4 pCi/L by year, Washburn County against Wisconsin2014 to 2023, years with 30 or more tests: Washburn County 35.5% to 44.9%, the state's pooled share 35.7% in 2023.
Washburn CountyWisconsin, pooled
Share of reported tests at or above 4 pCi/L by year, Washburn County against Wisconsin: data table
YearTestsWashburn County, at or above 4 pCi/LWisconsin, pooled
20143135.5%51.1%
20153545.7%51.6%
20163129.0%45.2%
20173138.7%44.8%
20193339.4%42.9%
20213928.2%39.9%
20223432.4%42.9%
20234944.9%35.7%
Washburn County against Wisconsin, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Washburn County
Washburn County4944.9%3.1 pCi/LThis county
Wisconsin, pooled72 counties, pooled20,87935.7%Not pooled−9.2 points
United States, pooled642 counties, pooled128,74033.4%Not pooled−11.5 points
Langlade Countyhighest in the state22565.8%6.0 pCi/L+20.9 points
Juneau Countylowest in the state5010.0%1.1 pCi/L−34.9 points
Sawyer County, WIborders it4742.6%3.2 pCi/L−2.3 points
Rusk County, WIborders it5738.6%3.2 pCi/L−6.3 points
Barron County, WIborders it19934.7%2.5 pCi/L−10.2 points
Burnett County, WIborders it5223.1%1.6 pCi/L−21.8 points
Douglas County, WIborders it449.1%1.5 pCi/L−35.8 points
Bayfield County, WIborders it355.7%1.5 pCi/L−39.2 points
Where Washburn County's reported results fell, 2023, beside Wisconsin and the United States
ResultWashburn County testsWashburn County shareWisconsin shareU.S. shareAgainst Wisconsin
Under 2 pCi/L1632.7%41.4%41.4%−8.7 points
2 to 4 pCi/L1122.4%23.0%25.2%−0.6 points
4 pCi/L and above2244.9%35.7%33.4%+9.2 points
Washburn County ranked among the 69 Wisconsin counties with 30 or more tests, by share at or above 4 pCi/L, 2023
CountyRankTestsAt or above 4 pCi/LMedian
Rock County12 of 6945149.9%3.9 pCi/L
Grant County13 of 6932348.3%3.5 pCi/L
Washington County14 of 6939947.9%3.8 pCi/L
Vernon County15 of 6916247.5%3.8 pCi/L
Ozaukee County16 of 6944545.8%3.6 pCi/L
Washburn County17 of 694944.9%3.1 pCi/L
Kewaunee County18 of 695644.6%3.7 pCi/L
Marinette County19 of 696144.3%2.6 pCi/L
Jefferson County20 of 6929644.3%3.5 pCi/L
Waukesha County21 of 691,63343.2%3.2 pCi/L
Sheboygan County22 of 6939942.9%3.3 pCi/L
Washburn County radon tests by year, against Wisconsin's pooled share
YearTestsAt or above 4 pCi/LMedianHighestWisconsin, pooledChange from the row before
20234944.9%3.1 pCi/L16.0 pCi/L35.7%+12.5 points
20223432.4%2.6 pCi/L16.2 pCi/L42.9%+4.2 points
20213928.2%2.4 pCi/L13.5 pCi/L39.9%+0.6 points
20202927.6%3.1 pCi/L10.6 pCi/L27.0%−11.8 points
20193339.4%3.2 pCi/L19.7 pCi/L42.9%+0.7 points
20173138.7%2.9 pCi/L13.4 pCi/L44.8%+9.7 points
20163129.0%2.8 pCi/L12.9 pCi/L45.2%−16.7 points
20153545.7%3.4 pCi/L21.7 pCi/L51.6%+10.2 points
20143135.5%1.3 pCi/L41.3 pCi/L51.1%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Washburn County, Geology

The ground under Washburn County

Predicted

USGS's geologic map puts all of Washburn County's mapped land in one class: moderate radon potential. The map puts 93.3% of Washburn County in the area it calls Superior Lobe and 5.6% in Chippewa, Wisconsin Valley, and Langlade sublobes of the Superior Lobe, with one smaller area beside them. USGS gives both a radon index of 10, in the moderate band (9 to 11).

USGS's geologic areas under Washburn County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Superior LobeGlacial deposits derived from sandstone and volcanic rocks.Moderate1093.3%
Chippewa, Wisconsin Valley, and Langlade sublobes of the Superior LobeGranite, granite-derived glacial deposits, and mafic volcanic rocks.Moderate105.6%
Central Plain/Northern HighlandPre-Late Wisconsinan glacial deposits derived from sandstone and carbonate rocks.Moderate101.1%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Washburn County beside the ground around it

Across Wisconsin 34.8% of the land is rated high; none of Washburn County's is. Of the 6 counties that border it, 1 has more high-potential ground, Burnett County the most at 0.3%.

Share of land by USGS radon potential: Washburn County, the 6 counties bordering it and Wisconsin
AreaEPA zoneLow potentialModerate potentialHigh potential
Washburn CountyZone 2None100%None
Barron CountyZone 2None100%None
Burnett CountyZone 2None99.7%0.3%
Sawyer CountyZone 2None100%None
Rusk CountyZone 2None100%None
Bayfield CountyZone 2None98.9%None
Douglas CountyZone 2None99.5%None
Wisconsin72 counties, pooled by land areaVaries1.4%63.5%34.8%

The map rates the ground, not the air in any home.

Local help

Washburn County, Local resources

Radon testing and mitigation in Washburn County

What Wisconsin's program says
Phone
1-888-569-7236
Email
DHSRadon@dhs.wisconsin.gov
Licensing of radon professionals
The State of Wisconsin does not require contractors performing radon measurement or mitigation work to be state licensed or nationally certified.

What it means

Washburn County, Questions

Questions about radon in Washburn County

Are radon levels high in Washburn County?

In 2023, 44.9% of the radon tests reported to CDC for Washburn County, Wisconsin were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.1 pCi/L. Of 69 Wisconsin counties with 30 or more tests for the same period, 16 reported a higher share; pooled, the state comes to 35.7%.

Which counties border Washburn County?

Washburn County borders 6 counties: Barron County, Burnett County, Sawyer County, Rusk County, Bayfield County and Douglas County.

Products

Washburn County, Products

Testing a home in Washburn County

In Washburn County, 44.9% of 49 tests reported to CDC in 2023 reached 4 pCi/L, against 35.7% pooled across Wisconsin. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Washburn County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Washburn County homes, compared

Explore

Washburn County, Bordering counties

Counties bordering Washburn County

Calculated by Radon411

Washburn County, Cities and towns

Cities and towns in Washburn County

The Census Bureau estimates 17,087 residents in Washburn County for July 1, 2025, 469 more than in 2020 (+2.8%). That works out to 21 people per square mile of land. No town dominates: Spooner, the largest, has 2,531 residents, 14.8% of the total. Together its 4 incorporated places hold 28.8% of those residents; the other 71.2% live outside any of them. CDC's 49 reported tests for 2023 work out to 2.9 per 1,000 residents (2025 estimate), close to Wisconsin's 3.5.

From Spooner to Birchwood, CDC publishes no figure by town: each reads Washburn County's.

The cities and towns in Washburn County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Spooner2,531+2.1%14.8%
Shell Lake1,414+3.8%8.3%
Minong556+1.6%3.3%
Birchwood412+2.2%2.4%

4 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).

Washburn County, Homes

Homes in Washburn County

Washburn County is a place of houses on their own lots: 87% of its 12,823 homes are detached single-family houses, against 66% across Wisconsin. Half of its homes were built before 1982, close to Wisconsin's 1975: 22% date from before 1960 and 26% from 2000 or later. Owners live in 81% of the occupied homes (Wisconsin: 68%), so for most households a test and a fix are their own to order.

Homes in Washburn County, Wisconsin, 2019 to 2023
HomesWashburn CountyWisconsin
Housing units12,8232,750,750
Detached houses87%66%
In buildings of 5 or more2%17%
Mobile homes6%3%
Built before 196022%34%
Built since 200026%20%
Middle year built19821975
Owner-occupied81%68%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.