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 Webster County, Iowa
EPA puts Webster County in Zone 1, its highest radon zone, and high results are common there: 69.4% of the 1,189 radon tests reported to CDC (2008 to 2017, laboratory totals) 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
69.4%
10.9 pts above IA
- Webster
- 69.4%
- Iowa
- 58.5%
1,189 tests, 2008 to 2017
Median result
6.5pCi/L
Action level reached
- Webster
- 6.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,189
16th of 99 by tests
- Webster
- 1,189
- Polk
- 10,945
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Iowa
35 of 99
Middle half
- Webster
- 69.4%
- Sioux
- 84.2%
By share, of 99 with 30+ tests
Read a result for Webster County
Starts at Webster County's median, 6.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 6.5 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. Webster County's median reported result, 2008 to 2017.
The data
Webster County, At a glance
Webster County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Webster 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 Webster County, 2008 to 2017, laboratory
Under 2 pCi/L: 15%2 to 4 pCi/L: 15%4 pCi/L and above: 70%
Of 1,189 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 183 | 15.4% |
| 2 to 4 pCi/L | 181 | 15.2% |
| 4 pCi/L and above | 825 | 69.4% |
What these figures count
These are the 1,189 tests reported to CDC for Webster County over 2008 to 2017 (laboratory totals), 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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Webster County, Compared
Webster County radon figures, compared
Calculated by Radon411More than half: 69.4% of the 1,189 radon tests reported to CDC for Webster County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 35th of 99 Iowa counties with 30 or more tests for the same period. That is 10.9 points above the 58.5% pooled from 99 Iowa counties.
The median result, 6.5 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 88.3 pCi/L. The rest split 15.4% under 2 pCi/L and 15.2% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 69.4% share point the same way here.
3 of its 7 bordering counties with figures ran higher, led by Greene County at 71.3%; Hamilton County reported 64.3%. Statewide for the same period, Sioux County reported the highest share (84.2%) and Decatur County the lowest (25.9%).
CDC's ten-year totals for Webster County went from 733 tests (2005 to 2014) to 1,189 (2008 to 2017), the share going from 71.6% to 69.4%.
Nationally, every county with a figure for the same period pools to 35.7%; Webster County sits 33.7 points above it. CDC also counts 102 tests taken after mitigation in Webster County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Webster County, Geology
The ground under Webster County
PredictedUSGS's geologic map puts all of Webster County's mapped land in one class: high radon potential. All of it lies in the area the map calls Des Moines Lobe, 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 |
|---|---|---|---|---|
| Des Moines Lobe | Calcareous loamy till derived from shale, limestone, dolomite, sandstone. | High | 12 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Webster County beside the ground around it
On high-potential ground Webster County is close to Iowa as a whole: 100% of its land against 98.8%. Of the 7 counties that border it, none has as large a share of high-potential ground; Boone County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Webster County, Local resources
Radon testing and mitigation in Webster County
Listed radon businesses with an address in Webster County:
- Iowa HHS Radon ProgramIowa HHS Radon Program, run by Iowa Department of Health and Human Services, licenses or certifies radon professionals, offers free or discounted test kits and states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in Iowa.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
You can reach the Hotline by calling 1-800-383-5992 to order low-cost radon test kits and find answers to your radon questions.
- Compare kits
- Professionals in Iowa185 professionals are listed in Iowa.
Listed radon professionals by town: Fort Dodge
What Iowa's program says
- Phone
- (515) 281-4928
- Licensing of radon professionals
Iowa’s radon program approves applications for persons who wish to become certified to perform radon testing or credentialed to perform mitigation and laboratories that provide radon testing devices and analytical services.
- Disclosure when a home is sold or rented
However, per Iowa Code chapters 543B.9 and 543B.18 and Iowa Administrative Code 193E Chapter 14 administered by the Iowa Real Estate Commission, a seller must disclose any known tests for the presence of radon and if yes, provide the date of last report and the result(s).
What it means
Webster County, Questions
Questions about radon in Webster County
Are radon levels high in Webster County?
Over the 2008 to 2017 laboratory totals, 69.4% of the radon tests reported to CDC for Webster County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 6.5 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 34 reported a higher share; pooled, the state comes to 58.5%.
Which counties border Webster County?
Webster County borders 7 counties: Calhoun County, Hamilton County, Boone County, Greene County, Humboldt County, Wright County and Pocahontas County.
Products
Webster County, Products
Testing a home in Webster County
In Webster County, 69.4% of 1,189 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 58.5% pooled across Iowa. In Zone 1 the year-round level in Webster 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
EcoQube Wi-Fi continuous radon monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Wi-Fi
- App only
Method: Ion chamber
First reading: Within 10 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
Webster County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Webster County
Explore
Webster County, Bordering counties
Counties bordering Webster County
Calculated by Radon411- Radon levels in Greene CountyEPA zone 1
71.3%at or above 4 pCi/L
Median 6.2 pCi/L · 143 tests · 1.9 points above Webster County
- Radon levels in Humboldt CountyEPA zone 1
70.1%at or above 4 pCi/L
Median 7.0 pCi/L · 385 tests · 0.7 points above Webster County
- Radon levels in Calhoun CountyEPA zone 1
69.8%at or above 4 pCi/L
Median 6.1 pCi/L · 507 tests · 0.4 points above Webster County
- Radon levels in Pocahontas CountyEPA zone 1
68.8%at or above 4 pCi/L
Median 6.4 pCi/L · 417 tests · 0.6 points below Webster County
- Radon levels in Boone CountyEPA zone 1
68.7%at or above 4 pCi/L
Median 6.0 pCi/L · 1,134 tests · 0.7 points below Webster County
- Radon levels in Wright CountyEPA zone 1
66.8%at or above 4 pCi/L
Median 6.2 pCi/L · 292 tests · 2.6 points below Webster County
- Radon levels in Hamilton CountyEPA zone 1
64.3%at or above 4 pCi/L
Median 5.5 pCi/L · 252 tests · 5.1 points below Webster County
Webster County, Cities and towns
Cities and towns in Webster County
Webster County's population has barely moved since 2020: 36,838 residents on July 1, 2025 against 36,997 then, by the Census Bureau's estimates. That works out to 51 people per square mile of land. Fort Dodge alone is home to 24,837 of them, 67.4% of the total. CDC's 1,189 reported tests for 2008 to 2017 work out to 32.3 per 1,000 residents (2025 estimate), close to Iowa's 29.4.
From Fort Dodge to Vincent, CDC publishes no figure by town: each reads Webster County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Fort Dodge | 24,837 | −0.2% | 67.4% |
| Gowrie | 943 | −1.2% | 2.6% |
| Dayton | 758 | −2.4% | 2.1% |
| Stratfordextends beyond Webster County | 698 | −1.3% | Counted whole |
| Badger | 540 | +2.5% | 1.5% |
| Otho | 420 | −2.1% | 1.1% |
| Lehigh | 396 | −0.8% | 1.1% |
| Duncombe | 369 | −2.1% | 1.0% |
| Callender | 360 | −3.2% | 1.0% |
| Farnhamvilleextends beyond Webster County | 358 | −5.5% | Counted whole |
| Harcourt | 257 | −3.0% | 0.7% |
| Barnum | 194 | +10.2% | 0.5% |
- Moorland
- Clare
- Vincent
15 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Webster County is counted whole, so it has no share.
Webster County, Homes
Homes in Webster County
Webster County is a place of houses on their own lots: 77% of its 17,053 homes are detached single-family houses, against 72% across Iowa. The homes are older than Iowa's as a whole: half were built before 1957 (1971 for Iowa), and 55% date from before 1960. 70% of occupied homes are lived in by their owner (Iowa: 72%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Webster County | Iowa |
|---|---|---|
| Housing units | 17,053 | 1,427,175 |
| Detached houses | 77% | 72% |
| In buildings of 5 or more | 9% | 14% |
| Mobile homes | 3% | 3% |
| Built before 1960 | 55% | 39% |
| Built since 2000 | 10% | 21% |
| Middle year built | 1957 | 1971 |
| Owner-occupied | 70% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.