Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Manitowoc County, Wisconsin
EPA puts Manitowoc County in Zone 2, its middle radon zone, and 31.1% of its 209 reported radon tests (2023) were 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
31.1%
4.6 pts below WI
- Manitowoc
- 31.1%
- Wisconsin
- 35.7%
209 tests, 2023
Median result
2.2pCi/L
Below action level
- Manitowoc
- 2.2 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
209
29th of 69 by tests
- Manitowoc
- 209
- 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
49 of 69
Middle half
- Manitowoc
- 31.1%
- Langlade
- 65.8%
By share, of 69 with 30+ tests
Read a result for Manitowoc County
Starts at Manitowoc County's median, 2.2 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.2 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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. Manitowoc County's median reported result, 2023.
The data
Manitowoc County, At a glance
Manitowoc County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Manitowoc County is a
USGS geologic potential: Low across 48% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Manitowoc County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 39.3% |
| 2015 | 52.6% |
| 2016 | 28.2% |
| 2017 | 31.3% |
| 2019 | 34.3% |
| 2020 | 23.7% |
| 2021 | 34.0% |
| 2022 | 39.4% |
| 2023 | 31.1% |
2023: 31.1%. Across these years the share ran from 23.7% to 52.6%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 209 tests reported to CDC for Manitowoc 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).
Manitowoc County, Compared
Manitowoc County radon figures, compared
Calculated by Radon411In Manitowoc County, about 3 in 10 reported tests in 2023 (65 of 209) were at or above EPA's action level. Against the national pool of 33.4%, the gap is 2.3 points lower. Across 72 Wisconsin counties pooled together, 35.7% of tests reached that level, so Manitowoc County runs 4.6 points below its state.
Of 4 neighbours with a figure, 3 reported a larger share at or above 4 pCi/L and 1 a smaller one; the spread is 23.0% (Brown County) to 51.6% (Calumet County). By share, Manitowoc County is 49th of 69 Wisconsin counties with 30 or more tests for the same period.
Year by year, 2014 opened at 39.3% and 2023 closed at 31.1% (down 8.2 points), with 2015 the high at 52.6%. Half the tests came in under 2.2 pCi/L and half over it; the single highest reached 39.5 pCi/L. Below the action level, 99 tests (47.4%) came in under 2 pCi/L, against 41.4% statewide, and 45 tests (21.5%) 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 31.1% share point the same way here. USGS geology rates 48% of the county's land low radon potential. CDC also counts 7 tests taken after mitigation in Manitowoc County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2016, with 241 tests reported; the quietest, 2022, had 99.
Manitowoc CountyWisconsin, pooled
| Year | Tests | Manitowoc County, at or above 4 pCi/L | Wisconsin, pooled |
|---|---|---|---|
| 2014 | 135 | 39.3% | 51.1% |
| 2015 | 152 | 52.6% | 51.6% |
| 2016 | 241 | 28.2% | 45.2% |
| 2017 | 214 | 31.3% | 44.8% |
| 2019 | 172 | 34.3% | 42.9% |
| 2020 | 135 | 23.7% | 27.0% |
| 2021 | 147 | 34.0% | 39.9% |
| 2022 | 99 | 39.4% | 42.9% |
| 2023 | 209 | 31.1% | 35.7% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Manitowoc County, Geology
The ground under Manitowoc County
PredictedNo class of ground holds half of Manitowoc County on USGS's geologic map: 47.6% of its land is low radon potential, 14.7% high and 37.2% moderate. The map puts 47.6% of Manitowoc County in the area it calls Eastern Ridges and Lowlands and 37.2% in Green Bay Lobe, with one smaller area beside them. USGS gives the first a radon index of 8, in the low band (5 to 8), and the second 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Eastern Ridges and Lowlands | Glacial lake deposits, clayey glacial deposits. | Low | 8 | 47.6% |
| Green Bay Lobe | Glacial deposits derived from carbonate and igneous rocks. | Moderate | 10 | 37.2% |
| Eastern Ridges and Lowlands | Glacial deposits derived from Ordovician carbonate rocks. | High | 12 | 14.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Manitowoc County beside the ground around it
Wisconsin as a whole has more high-potential ground than Manitowoc County: 34.8% of its land, against 14.7% here. Of the 4 counties that border it, 2 have more high-potential ground, Sheboygan County the most at 47.9%.
The map rates the ground, not the air in any home.
Local help
Manitowoc County, Local resources
Radon testing and mitigation in Manitowoc 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
Manitowoc County, Questions
Questions about radon in Manitowoc County
Are radon levels high in Manitowoc County?
In 2023, 31.1% of the radon tests reported to CDC for Manitowoc County, Wisconsin were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.2 pCi/L. Of 69 Wisconsin counties with 30 or more tests for the same period, 48 reported a higher share; pooled, the state comes to 35.7%.
Which counties border Manitowoc County?
Manitowoc County borders 4 counties: Calumet County, Brown County, Kewaunee County and Sheboygan County.
Products
Manitowoc County, Products
Testing a home in Manitowoc County
In Manitowoc County, 31.1% of 209 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 Manitowoc County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Monitor
RadonScan USB-powered radon monitor with a color screen
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
First reading: Within 5 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Manitowoc County, Bordering counties
Counties bordering Manitowoc County
Calculated by Radon411- Radon levels in Calumet CountyEPA zone 2
51.6%at or above 4 pCi/L
Median 4.4 pCi/L · 122 tests · 20.5 points above Manitowoc County
- Radon levels in Kewaunee CountyEPA zone 2
44.6%at or above 4 pCi/L
Median 3.7 pCi/L · 56 tests · 13.5 points above Manitowoc County
- Radon levels in Sheboygan CountyEPA zone 2
42.9%at or above 4 pCi/L
Median 3.3 pCi/L · 399 tests · 11.8 points above Manitowoc County
- Radon levels in Brown CountyEPA zone 2
23.0%at or above 4 pCi/L
Median 1.4 pCi/L · 551 tests · 8.1 points below Manitowoc County
Manitowoc County, Cities and towns
Cities and towns in Manitowoc County
Manitowoc County's population has barely moved since 2020: 81,710 residents on July 1, 2025 against 81,401 then, by the Census Bureau's estimates. That works out to 139 people per square mile of land. Its largest town, Manitowoc, has 34,671 residents, 42.4% of the total. CDC's 209 reported tests for 2023 work out to 2.6 per 1,000 residents (2025 estimate), close to Wisconsin's 3.5.
From Manitowoc to Kellnersville, CDC publishes no figure by town: each reads Manitowoc County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Manitowoc | 34,671 | Level | 42.4% |
| Two Rivers | 11,222 | −0.4% | 13.7% |
| Kielextends beyond Manitowoc County | 3,973 | +0.9% | Counted whole |
| Cleveland | 1,582 | +0.1% | 1.9% |
| Mishicot | 1,428 | −0.1% | 1.7% |
| Reedsville | 1,191 | −0.3% | 1.5% |
| Valders | 959 | +0.2% | 1.2% |
| Whitelaw | 756 | +2.0% | 0.9% |
| St. Nazianz | 715 | +0.3% | 0.9% |
| Francis Creek | 681 | +3.7% | 0.8% |
| Maribel | 350 | +4.2% | 0.4% |
| Kellnersville | 311 | −0.6% | 0.4% |
12 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 Manitowoc County is counted whole, so it has no share.
Manitowoc County, Homes
Homes in Manitowoc County
Of Manitowoc County's 37,960 homes, 73% are detached houses, against 66% across Wisconsin; 10% are in buildings of five or more homes. The homes are older than Wisconsin's as a whole: half were built before 1963 (1975 for Wisconsin), and 47% date from before 1960. Owners live in 76% of the occupied homes (Wisconsin: 68%), so for most households a test and a fix are their own to order.
| Homes | Manitowoc County | Wisconsin |
|---|---|---|
| Housing units | 37,960 | 2,750,750 |
| Detached houses | 73% | 66% |
| In buildings of 5 or more | 10% | 17% |
| Mobile homes | 3% | 3% |
| Built before 1960 | 47% | 34% |
| Built since 2000 | 12% | 20% |
| Middle year built | 1963 | 1975 |
| Owner-occupied | 76% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.