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
Locations and reports
Radon Levels in Lafayette County, Wisconsin
EPA puts Lafayette County in Zone 1, its highest radon zone, and high results are common there: 52.2% of the 46 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
Share at 4+ pCi/L
52.2%
16.5 pts above WI
- Lafayette
- 52.2%
- Wisconsin
- 35.7%
46 tests, 2023
Median result
4.2pCi/L
Action level reached
- Lafayette
- 4.2 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
46
63rd of 69 by tests
- Lafayette
- 46
- Dane
- 2,887
Reported to CDC before any fix, 2023
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Wisconsin
9 of 69
Top quarter
- Lafayette
- 52.2%
- Langlade
- 65.8%
By share, of 69 with 30+ tests
Read a result for Lafayette County
Starts at Lafayette County's median, 4.2 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.2 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Lafayette County's median reported result, 2023.
The data
Lafayette County, At a glance
Lafayette County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Lafayette County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Lafayette County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 75.6% |
| 2015 | 65.6% |
| 2016 | 44.4% |
| 2017 | 31.3% |
| 2019 | 72.2% |
| 2020 | 57.6% |
| 2021 | 54.5% |
| 2022 | 66.7% |
| 2023 | 52.2% |
2023: 52.2%. Across these years the share ran from 31.3% to 75.6%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 46 tests reported to CDC for Lafayette 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).
Lafayette County, Compared
Lafayette County radon figures, compared
Calculated by Radon411More than half: 52.2% of the 46 radon tests reported to CDC for Lafayette County in 2023 read at least 4 pCi/L. That places it 9th of 69 Wisconsin counties with 30 or more tests for the same period. That is 16.5 points above the 35.7% pooled from 72 Wisconsin counties.
The median result, 4.2 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 27.4 pCi/L. The rest split 17.4% under 2 pCi/L and 30.4% from 2 to 4 (Wisconsin: 41.4% and 23.0%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 52.2% share point the same way here.
1 of its 3 bordering counties with figures ran higher, led by Iowa County at 61.0%; Green County reported 33.6%. Statewide for the same period, Langlade County reported the highest share (65.8%) and Bayfield County the lowest (5.7%).
The busiest year on file was 2017, with 80 tests reported; the quietest, 2022, had 18.
Over 6 years of annual figures the share fell 23.4 points, from 75.6% in 2014 to 52.2% in 2023; its peak was 75.6% in 2014. Nationally, every county with a figure for the same period pools to 33.4%; Lafayette County sits 18.8 points above it.
Lafayette CountyWisconsin, pooled
52.2% % of tests35.7% % of tests
| Year | Tests | Lafayette County, at or above 4 pCi/L | Wisconsin, pooled |
|---|---|---|---|
| 2014 | 45 | 75.6% | 51.1% |
| 2015 | 32 | 65.6% | 51.6% |
| 2017 | 80 | 31.3% | 44.8% |
| 2019 | 36 | 72.2% | 42.9% |
| 2020 | 33 | 57.6% | 27.0% |
| 2023 | 46 | 52.2% | 35.7% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Lafayette County, Geology
The ground under Lafayette County
PredictedUSGS's geologic map puts all of Lafayette County's mapped land in one class: high radon potential. 98.7% of it lies in the area the map calls Driftless Area, to which USGS gives a radon index of 12, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Driftless Area | Cambrian sandstone and Ordovician limestone and dolostone. | High | 12 | 98.7% |
| Eastern Ridges and Lowlands | Glacial deposits derived from Ordovician carbonate rocks. | High | 12 | 1.2% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Lafayette County beside the ground around it
Lafayette County has more high-potential ground than Wisconsin as a whole: 100% of its land against 34.8%. Of the 5 counties that border it, none has as large a share of high-potential ground; Grant County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Lafayette County, Local resources
Radon testing and mitigation in Lafayette 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
Lafayette County, Questions
Questions about radon in Lafayette County
Are radon levels high in Lafayette County?
In 2023, 52.2% of the radon tests reported to CDC for Lafayette County, Wisconsin were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.2 pCi/L. Of 69 Wisconsin counties with 30 or more tests for the same period, 8 reported a higher share; pooled, the state comes to 35.7%.
Which counties border Lafayette County?
Lafayette County borders 5 counties: Jo Daviess County, IL, Iowa County, WI, Green County, WI, Stephenson County, IL and Grant County, WI.
Products
Lafayette County, Products
Testing a home in Lafayette County
In Lafayette County, 52.2% of 46 tests reported to CDC in 2023 reached 4 pCi/L, against 35.7% pooled across Wisconsin. In Zone 1 the year-round level in Lafayette County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
Monitor
Corentium Home 2 battery digital radon monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Screen, app
Method: Alpha spectrometry
Readings: Every 60 minutes
Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Lafayette County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Lafayette County
Explore
Lafayette County, Bordering counties
Counties bordering Lafayette County
Calculated by Radon411- Radon levels in Iowa County, WIEPA zone 1
61.0%at or above 4 pCi/L
Median 4.8 pCi/L · 146 tests · 8.8 points above Lafayette County
- Radon levels in Grant County, WIEPA zone 1
48.3%at or above 4 pCi/L
Median 3.5 pCi/L · 323 tests · 3.9 points below Lafayette County
- Radon levels in Green County, WIEPA zone 1
33.6%at or above 4 pCi/L
Median 2.1 pCi/L · 235 tests · 18.6 points below Lafayette County
- Radon levels in Jo Daviess County, ILEPA zone 1
No CDC figure for 2023; its page reads it against its own neighbours.
- Radon levels in Stephenson County, ILEPA zone 1
No CDC figure for 2023; its page reads it against its own neighbours.
Lafayette County, Cities and towns
Cities and towns in Lafayette County
Lafayette County is growing: the Census Bureau puts it at 17,478 residents on July 1, 2025, up 5.2% from 16,619 in 2020. That works out to 28 people per square mile of land. No town dominates: Darlington, the largest, has 2,490 residents, 14.2% of the total. CDC's 46 reported tests for 2023 work out to 2.6 per 1,000 residents (2025 estimate), close to Wisconsin's 3.5.
From Darlington to Gratiot, CDC publishes no figure by town: each reads Lafayette County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Darlington | 2,490 | +1.4% | 14.2% |
| Cuba Cityextends beyond Lafayette County | 2,103 | −1.7% | Counted whole |
| Shullsburg | 1,240 | +5.8% | 7.1% |
| Hazel Greenextends beyond Lafayette County | 1,173 | −0.3% | Counted whole |
| Belmont | 1,042 | +4.9% | 6.0% |
| Benton | 996 | +5.5% | 5.7% |
| Blanchardvilleextends beyond Lafayette County | 829 | +1.6% | Counted whole |
| Argyle | 822 | +4.6% | 4.7% |
| South Wayne | 448 | +0.2% | 2.6% |
| Gratiot | 234 | +4.0% | 1.3% |
10 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 Lafayette County is counted whole, so it has no share.
Lafayette County, Homes
Homes in Lafayette County
Lafayette County is a place of houses on their own lots: 84% of its 7,193 homes are detached single-family houses, against 66% across Wisconsin. The homes are older than Wisconsin's as a whole: half were built before 1964 (1975 for Wisconsin), and 47% date from before 1960. Owners live in 79% of the occupied homes (Wisconsin: 68%), so for most households a test and a fix are their own to order.
| Homes | Lafayette County | Wisconsin |
|---|---|---|
| Housing units | 7,193 | 2,750,750 |
| Detached houses | 84% | 66% |
| In buildings of 5 or more | 4% | 17% |
| Mobile homes | 5% | 3% |
| Built before 1960 | 47% | 34% |
| Built since 2000 | 16% | 20% |
| Middle year built | 1964 | 1975 |
| Owner-occupied | 79% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.