Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
Locations and reports
Radon Levels in Florence County, Wisconsin
EPA puts Florence County in Zone 2, its middle radon zone, and only 16 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
50.0%
2.2 pts above WI
- Florence
- 50.0%
- Wisconsin
- 47.8%
174 tests, 2005 to 2014
Median result
4.0pCi/L
Action level reached
- Florence
- 4.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2005 to 2014
Tests reported
174
51st of 71 by tests
- Florence
- 174
- Milwaukee
- 5,005
Reported to CDC before any fix, 2005 to 2014
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
26 of 71
Middle half
- Florence
- 50.0%
- Dodge
- 63.9%
By share, of 71 with 30+ tests
Read a result for Florence County
Starts at Florence County's median, 4.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 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. Florence County's median reported result, 2005 to 2014.
The data
Florence County, At a glance
Florence County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Florence County is a
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 Florence County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 64.7% |
| 2015 | 54.5% |
| 2016 | 55.9% |
| 2017 | 44.1% |
| 2019 | 35.7% |
| 2020 | 45.5% |
| 2021 | 36.4% |
| 2022 | 44.4% |
| 2023 | 43.8% |
2023: 43.8%. Across these years the share ran from 35.7% to 64.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 16 tests were reported to CDC for Florence County over 2023, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Florence County, Compared
Florence County radon figures, compared
Calculated by Radon411More than half: 50.0% of the 174 radon tests reported to CDC for Florence County over the 2005 to 2014 laboratory totals read at least 4 pCi/L. That places it 26th of 71 Wisconsin counties with 30 or more tests for the same period. That is 2.2 points above the 47.8% pooled from 72 Wisconsin counties.
The newest figure, in 2023, counts only 16 tests (43.8% at or above 4 pCi/L), too few to compare, so this reading uses the 174-test figure.
The median result, 4.0 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 80.8 pCi/L. The rest split 22.4% under 2 pCi/L and 27.6% from 2 to 4 (Wisconsin: 29.5% and 22.7%). The reported tests do not follow EPA's Zone 2 label for Florence County (predicted average between 2 and 4 pCi/L): 50.0% of them reached 4 pCi/L, fewer than that label suggests.
No bordering county with a figure for the same period reported a higher share; the closest is Dickinson County, MI at 37.1%, the lowest Marinette County at 22.0%. Statewide for the same period, Dodge County reported the highest share (63.9%) and Marquette County the lowest (12.5%).
The busiest year on file was 2016, with 68 tests reported; the quietest, 2022, had 9.
Over 3 years of annual figures the share fell 10.4 points, from 54.5% in 2015 to 44.1% in 2017; its peak was 55.9% in 2016. Nationally, every county with a figure for the same period pools to 36.0%; Florence County sits 14.0 points above it. CDC also counts 21 tests taken after mitigation in Florence County for the same period: tests in homes where a fix was already in.
Florence CountyWisconsin, pooled
| Year | Tests | Florence County, at or above 4 pCi/L | Wisconsin, pooled |
|---|---|---|---|
| 2015 | 33 | 54.5% | 51.6% |
| 2016 | 68 | 55.9% | 45.2% |
| 2017 | 34 | 44.1% | 44.8% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Florence County, Geology
The ground under Florence County
PredictedUSGS's geologic map puts all of Florence County's mapped land in one class: moderate radon potential. The map puts 92.5% of Florence County in the area it calls Chippewa, Wisconsin Valley, and Langlade sublobes of the Superior Lobe and 7.3% in Green Bay Lobe. USGS gives both 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 |
|---|---|---|---|---|
| Chippewa, Wisconsin Valley, and Langlade sublobes of the Superior Lobe | Granite, granite-derived glacial deposits, and mafic volcanic rocks. | Moderate | 10 | 92.5% |
| Green Bay Lobe | Glacial deposits derived from carbonate and igneous rocks. | Moderate | 10 | 7.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Florence County beside the ground around it
Across Wisconsin 34.8% of the land is rated high; none of Florence County's is. Of the 4 counties that border it, 2 have more high-potential ground, Marinette County the most at 4.1%.
The map rates the ground, not the air in any home.
Local help
Florence County, Local resources
Radon testing and mitigation in Florence 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
Florence County, Questions
Questions about radon in Florence County
Are radon levels high in Florence County?
In 2023, 43.8% of the radon tests reported to CDC for Florence County, Wisconsin were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.7 pCi/L. Of 71 Wisconsin counties with 30 or more tests for the same period, 25 reported a higher share; pooled, the state comes to 47.8%.
Which counties border Florence County?
Florence County borders 4 counties: Iron County, MI, Forest County, WI, Dickinson County, MI and Marinette County, WI.
Products
Florence County, Products
Testing a home in Florence County
In Florence County, 50.0% of 174 tests reported to CDC over the 2005 to 2014 laboratory totals reached 4 pCi/L, against 47.8% pooled across Wisconsin. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Florence 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
MonitorX-Sense
XR0A-SR battery digital radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Florence County, Bordering counties
Counties bordering Florence County
Calculated by Radon411- Radon levels in Dickinson County, MIEPA zone 2
37.1%at or above 4 pCi/L
Median 2.9 pCi/L · 625 tests · 12.9 points below Florence County
- Radon levels in Iron County, MIEPA zone 2
36.8%at or above 4 pCi/L
Median 3.0 pCi/L · 223 tests · 13.2 points below Florence County
- Radon levels in Forest County, WIEPA zone 2
28.8%at or above 4 pCi/L
Median 2.5 pCi/L · 132 tests · 21.2 points below Florence County
- Radon levels in Marinette County, WIEPA zone 2
22.0%at or above 4 pCi/L
Median 1.8 pCi/L · 336 tests · 28.0 points below Florence County
Florence County, Residents
Who lives in Florence County
The Census Bureau estimates 4,748 residents in Florence County for July 1, 2025, 183 more than in 2020 (+4.0%). Spread over its land, that is 9.7 people to the square mile. Testing is reported here more often than across the state: CDC's 174 reported tests for 2005 to 2014 come to 36.6 for every 1,000 residents (2025 estimate), against 9.5 for Wisconsin.
Census lists no incorporated place in Florence County: every home in it reads the county's figures.
Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Florence County, Homes
Homes in Florence County
Florence County is a place of houses on their own lots: 87% of its 4,659 homes are detached single-family houses, against 66% across Wisconsin. Half of its homes were built before 1979, close to Wisconsin's 1975: 31% date from before 1960 and 23% from 2000 or later. Owners live in 90% of the occupied homes (Wisconsin: 68%), so for most households a test and a fix are their own to order.
| Homes | Florence County | Wisconsin |
|---|---|---|
| Housing units | 4,659 | 2,750,750 |
| Detached houses | 87% | 66% |
| In buildings of 5 or more | 2% | 17% |
| Mobile homes | 9% | 3% |
| Built before 1960 | 31% | 34% |
| Built since 2000 | 23% | 20% |
| Middle year built | 1979 | 1975 |
| Owner-occupied | 90% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.