Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Hughes County, South Dakota
EPA puts Hughes County in Zone 1, its highest radon zone, and high results are common there: 70.4% of the 71 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
70.4%
11.9 pts above SD
- Hughes
- 70.4%
- SD
- 58.5%
71 tests, 2008 to 2017
Median result
5.7pCi/L
Action level reached
- Hughes
- 5.7 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
71
14th of 23 by tests
- Hughes
- 71
- Minnehaha
- 1,920
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 SD
5 of 23
Top quarter
- Hughes
- 70.4%
- Lake
- 76.0%
By share, of 23 with 30+ tests
Read a result for Hughes County
Starts at Hughes County's median, 5.7 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 5.7 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. Hughes County's median reported result, 2008 to 2017.
The data
Hughes County, At a glance
Hughes County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Hughes 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 Hughes County, 2008 to 2017, laboratory
Under 2 pCi/L: 17%2 to 4 pCi/L: 13%4 pCi/L and above: 70%
Of 71 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 12 | 16.9% |
| 2 to 4 pCi/L | 9 | 12.7% |
| 4 pCi/L and above | 50 | 70.4% |
What these figures count
These are the 71 tests reported to CDC for Hughes 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).
Hughes County, Compared
Hughes County radon figures, compared
Calculated by Radon411More than half: 70.4% of the 71 radon tests reported to CDC for Hughes County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 5th of 23 South Dakota counties with 30 or more tests for the same period. That is 11.9 points above the 58.5% pooled from 62 South Dakota counties.
The median result, 5.7 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 31.4 pCi/L. The rest split 16.9% under 2 pCi/L and 12.7% from 2 to 4 (South Dakota: 23.6% and 17.9%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 70.4% share point the same way here.
Statewide for the same period, Lake County reported the highest share (76.0%) and Davison County the lowest (48.8%).
CDC's ten-year totals for Hughes County went from 33 tests (2005 to 2014) to 71 (2008 to 2017), the share going from 66.7% to 70.4%.
Nationally, every county with a figure for the same period pools to 35.7%; Hughes County sits 34.7 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Hughes County, Geology
The ground under Hughes County
PredictedUSGS's geologic map puts all of Hughes County's mapped land in one class: high radon potential. All of it lies in the area the map calls Missouri Coteau/James River Lowland/Coteau des Prairies, to which USGS gives a radon index of 14, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Missouri Coteau/James River Lowland/Coteau des Prairies | Glacial drift derived largely from Cretaceous marine shale. | High | 14 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Hughes County beside the ground around it
Hughes County has more high-potential ground than South Dakota as a whole: 100% of its land against 56.7%. Of the 4 counties that border it, none has as large a share of high-potential ground; Hyde County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Hughes County, Local resources
Radon testing and mitigation in Hughes County
- South Dakota's radon programDepartment of Agriculture and Natural ResourcesSouth Dakota's radon program offers free or discounted test kits, and answers questions about testing and mitigation in South Dakota.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The Department of Agriculture and Natural Resources (DANR) will provide 500 free Radon test kits to South Dakota Residents.
- Compare kits
- Professionals in South Dakota5 professionals are listed in South Dakota.
What South Dakota's program says
- Phone
- 1-800-438-3367
What it means
Hughes County, Questions
Questions about radon in Hughes County
Are radon levels high in Hughes County?
Over the 2008 to 2017 laboratory totals, 70.4% of the radon tests reported to CDC for Hughes County, South Dakota were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.7 pCi/L. Of 23 South Dakota counties with 30 or more tests for the same period, 4 reported a higher share; pooled, the state comes to 58.5%.
Which counties border Hughes County?
Hughes County borders 4 counties: Hyde County, Sully County, Lyman County and Stanley County.
Products
Hughes County, Products
Testing a home in Hughes County
In Hughes County, 70.4% of 71 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 58.5% pooled across South Dakota. In Zone 1 the year-round level in Hughes 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
Wave Plus battery radon and air quality monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- App only
Method: Alpha spectrometry
Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Hughes County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Hughes County
Explore
Hughes County, Bordering counties
Counties bordering Hughes County
Calculated by Radon411- Radon levels in Sully CountyEPA zone 1
100.0%at or above 4 pCi/L
Median 4.1 pCi/L · 1 test · 29.6 points above Hughes County
- Radon levels in Lyman CountyEPA zone 1
100.0%at or above 4 pCi/L
Median 22.1 pCi/L · 2 tests · 29.6 points above Hughes County
- Radon levels in Stanley CountyEPA zone 1
66.7%at or above 4 pCi/L
Median 4.2 pCi/L · 3 tests · 3.7 points below Hughes County
- Radon levels in Hyde CountyEPA zone 1
57.1%at or above 4 pCi/L
Median 4.9 pCi/L · 7 tests · 13.3 points below Hughes County
Hughes County, Cities and towns
Cities and towns in Hughes County
About 17,570 people live in Hughes County by the Census Bureau's estimate for July 1, 2025, 164 fewer than in 2020 (−0.9%). That works out to 24 people per square mile of land. Pierre alone is home to 13,848 of them, 78.8% of the total. Together its 3 incorporated places hold 81.2% of those residents; the other 18.8% live outside any of them. Reported testing is thin here: 71 tests over 2008 to 2017, or 4.0 for every 1,000 residents (2025 estimate), where South Dakota as a whole comes to 6.7.
From Pierre to Harrold, CDC publishes no figure by town: each reads Hughes County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Pierre | 13,848 | −1.5% | 78.8% |
| Blunt | 330 | −3.2% | 1.9% |
| Harrold | 96 | −4.0% | 0.5% |
3 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).
Hughes County, Homes
Homes in Hughes County
Of Hughes County's 7,957 homes, 65% are detached houses, against 67% across South Dakota; 15% are in buildings of five or more homes. Half of its homes were built before 1978, close to South Dakota's 1979: 26% date from before 1960 and 22% from 2000 or later. Owners live in 75% of the occupied homes (South Dakota: 69%), so for most households a test and a fix are their own to order.
| Homes | Hughes County | South Dakota |
|---|---|---|
| Housing units | 7,957 | 402,364 |
| Detached houses | 65% | 67% |
| In buildings of 5 or more | 15% | 16% |
| Mobile homes | 13% | 8% |
| Built before 1960 | 26% | 29% |
| Built since 2000 | 22% | 28% |
| Middle year built | 1978 | 1979 |
| Owner-occupied | 75% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.