Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
Locations and reports
Radon Levels in Bayfield County, Wisconsin
EPA puts Bayfield County in Zone 2, its middle radon zone, and most reported tests there come back low, though 5.7% of 35 (2023) reached 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
5.7%
30.0 pts below WI
- Bayfield
- 5.7%
- Wisconsin
- 35.7%
35 tests, 2023
Median result
1.5pCi/L
Below action level
- Bayfield
- 1.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
35
69th of 69 by tests
- Bayfield
- 35
- Dane
- 2,887
Reported to CDC before any fix, 2023
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Wisconsin
69 of 69
Lowest quarter
- Bayfield
- 5.7%
- Langlade
- 65.8%
By share, of 69 with 30+ tests
Read a result for Bayfield County
Starts at Bayfield County's median, 1.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.5 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Bayfield County's median reported result, 2023.
The data
Bayfield County, At a glance
Bayfield County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Bayfield County is a
USGS geologic potential: Moderate across 99% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Bayfield County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 21.7% |
| 2015 | 36.8% |
| 2016 | 25.7% |
| 2017 | 29.7% |
| 2019 | 27.3% |
| 2020 | 17.7% |
| 2021 | 35.3% |
| 2022 | 33.3% |
| 2023 | 5.7% |
2023: 5.7%. Across these years the share ran from 5.7% to 36.8%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 35 tests reported to CDC for Bayfield 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).
Bayfield County, Compared
Bayfield County radon figures, compared
Calculated by Radon411Bayfield County reports fewer high tests than Wisconsin overall. 5.7% of its 35 tests in 2023 were at or above 4 pCi/L. That is 30.0 points below the 35.7% pooled from 72 Wisconsin counties.
Ordered from highest share down, it comes 69th of 69 Wisconsin counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 33.4%; Bayfield County sits 27.7 points below it.
Next door, the shares run from 9.1% in Douglas County to 44.9% in Washburn County. The reported tests do not follow EPA's Zone 2 label for Bayfield County (predicted average between 2 and 4 pCi/L): 5.7% of them reached 4 pCi/L, fewer than that label suggests.
Half the tests came in under 1.5 pCi/L and half over it; the single highest reached 14.5 pCi/L. The rest split 54.3% under 2 pCi/L and 40.0% from 2 to 4 (Wisconsin: 41.4% and 23.0%). Year by year, 2014 opened at 21.7% and 2023 closed at 5.7% (down 16.0 points), with 2015 the high at 36.8%.
The busiest year on file was 2017, with 74 tests reported; the quietest, 2023, had 35.
Bayfield CountyWisconsin, pooled
5.7% % of tests35.7% % of tests
| Year | Tests | Bayfield County, at or above 4 pCi/L | Wisconsin, pooled |
|---|---|---|---|
| 2014 | 46 | 21.7% | 51.1% |
| 2015 | 68 | 36.8% | 51.6% |
| 2016 | 70 | 25.7% | 45.2% |
| 2017 | 74 | 29.7% | 44.8% |
| 2019 | 44 | 27.3% | 42.9% |
| 2020 | 62 | 17.7% | 27.0% |
| 2021 | 51 | 35.3% | 39.9% |
| 2022 | 39 | 33.3% | 42.9% |
| 2023 | 35 | 5.7% | 35.7% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Bayfield County, Geology
The ground under Bayfield County
PredictedUSGS's geologic map puts all of Bayfield County's mapped land in one class: moderate radon potential. 98.8% of it lies in the area the map calls Superior Lobe, to which USGS gives a radon index of 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Superior Lobe | Glacial deposits derived from sandstone and volcanic rocks. | Moderate | 10 | 98.8% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Bayfield County beside the ground around it
Across Wisconsin 34.8% of the land is rated high; none of Bayfield County's is. Of the 4 counties that border it, 3 have more moderate-potential ground, Washburn County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Bayfield County, Local resources
Radon testing and mitigation in Bayfield County
- Wisconsin's radon programWisconsin Department of Health ServicesWisconsin's radon program does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Wisconsin.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
We recommend starting with your regional Radon Information Center since many centers provide test kits for free or reduced cost, and often with laboratory fees covered.
- Compare kits
- Professionals in Wisconsin19 professionals are listed in Wisconsin.
What Wisconsin's program says
- Phone
- 1-888-569-7236
- 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
Bayfield County, Questions
Questions about radon in Bayfield County
Are radon levels high in Bayfield County?
In 2023, 5.7% of the radon tests reported to CDC for Bayfield County, Wisconsin were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Of 69 Wisconsin counties with 30 or more tests for the same period, 68 reported a higher share; pooled, the state comes to 35.7%.
Which counties border Bayfield County?
Bayfield County borders 4 counties: Ashland County, Douglas County, Sawyer County and Washburn County.
Products
Bayfield County, Products
Testing a home in Bayfield County
In Bayfield County, 5.7% of 35 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 Bayfield County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
MonitorAEGTEST
HOUND-1085 palm-sized rechargeable radon detector
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Bayfield County, Bordering counties
Counties bordering Bayfield County
Calculated by Radon411- Radon levels in Washburn CountyEPA zone 2
44.9%at or above 4 pCi/L
Median 3.1 pCi/L · 49 tests · 39.2 points above Bayfield County
- Radon levels in Sawyer CountyEPA zone 2
42.6%at or above 4 pCi/L
Median 3.2 pCi/L · 47 tests · 36.9 points above Bayfield County
- Radon levels in Ashland CountyEPA zone 2
29.3%at or above 4 pCi/L
Median 2.3 pCi/L · 41 tests · 23.6 points above Bayfield County
- Radon levels in Douglas CountyEPA zone 2
9.1%at or above 4 pCi/L
Median 1.5 pCi/L · 44 tests · 3.4 points above Bayfield County
Bayfield County, Cities and towns
Cities and towns in Bayfield County
The Census Bureau estimates 16,787 residents in Bayfield County for July 1, 2025, 547 more than in 2020 (+3.4%). That works out to 11 people per square mile of land. Ashland, the largest place on its list (7,927 residents in all), extends beyond Bayfield County, so no share of the total is worked out for it. Reported testing is thin here: 35 tests over 2023, or 2.1 for every 1,000 residents (2025 estimate), where Wisconsin as a whole comes to 3.5.
From Ashland to Mason, CDC publishes no figure by town: each reads Bayfield County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Ashlandextends beyond Bayfield County | 7,927 | +0.2% | Counted whole |
| Washburn | 2,045 | +0.1% | 12.2% |
| Bayfield | 589 | Level | 3.5% |
| Mason | 104 | +1.0% | 0.6% |
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). A place that extends beyond Bayfield County is counted whole, so it has no share.
Bayfield County, Homes
Homes in Bayfield County
Bayfield County is a place of houses on their own lots: 86% of its 13,285 homes are detached single-family houses, against 66% across Wisconsin. Half of its homes were built before 1981, close to Wisconsin's 1975: 26% date from before 1960 and 26% from 2000 or later. Owners live in 85% of the occupied homes (Wisconsin: 68%), so for most households a test and a fix are their own to order.
| Homes | Bayfield County | Wisconsin |
|---|---|---|
| Housing units | 13,285 | 2,750,750 |
| Detached houses | 86% | 66% |
| In buildings of 5 or more | 3% | 17% |
| Mobile homes | 6% | 3% |
| Built before 1960 | 26% | 34% |
| Built since 2000 | 26% | 20% |
| Middle year built | 1981 | 1975 |
| Owner-occupied | 85% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.