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 Lyon County, Minnesota
EPA puts Lyon County in Zone 1, its highest radon zone, and high results are common there: 65.0% of the 80 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
65.0%
30.4 pts above MN
- Lyon
- 65.0%
- Minnesota
- 34.6%
80 tests, 2023
Median result
6.1pCi/L
Action level reached
- Lyon
- 6.1 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
80
38th of 62 by tests
- Lyon
- 80
- Hennepin
- 6,545
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 Minnesota
6 of 62
Top quarter
- Lyon
- 65.0%
- Renville
- 75.7%
By share, of 62 with 30+ tests
Read a result for Lyon County
Starts at Lyon County's median, 6.1 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 6.1 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. Lyon County's median reported result, 2023.
The data
Lyon County, At a glance
Lyon County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Lyon 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 Lyon County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 56.1% |
| 2015 | 67.6% |
| 2016 | 66.3% |
| 2017 | 66.7% |
| 2018 | 60.0% |
| 2019 | 63.6% |
| 2020 | 52.1% |
| 2021 | 61.0% |
| 2022 | 30.8% |
| 2023 | 65.0% |
2023: 65.0%. Across these years the share ran from 30.8% to 67.6%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 80 tests reported to CDC for Lyon 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).
Lyon County, Compared
Lyon County radon figures, compared
Calculated by Radon411More than half: 65.0% of the 80 radon tests reported to CDC for Lyon County in 2023 read at least 4 pCi/L. That places it 6th of 62 Minnesota counties with 30 or more tests for the same period. That is 30.4 points above the 34.6% pooled from 86 Minnesota counties.
The median result, 6.1 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 48.5 pCi/L. The rest split 18.8% under 2 pCi/L and 16.3% from 2 to 4 (Minnesota: 36.6% and 28.9%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 65.0% share point the same way here.
Redwood County, the one bordering county with a figure for the same period, reported 54.8%. Statewide for the same period, Renville County reported the highest share (75.7%) and Lake County the lowest (3.8%).
The busiest year on file was 2022, with 133 tests reported; the quietest, 2020, had 48.
Over 10 years of annual figures the share rose 8.9 points, from 56.1% in 2014 to 65.0% in 2023; its peak was 67.6% in 2015. Nationally, every county with a figure for the same period pools to 33.4%; Lyon County sits 31.6 points above it.
Lyon CountyMinnesota, pooled
65.0% % of tests34.6% % of tests
| Year | Tests | Lyon County, at or above 4 pCi/L | Minnesota, pooled |
|---|---|---|---|
| 2014 | 132 | 56.1% | 42.9% |
| 2015 | 105 | 67.6% | 43.6% |
| 2016 | 92 | 66.3% | 37.0% |
| 2017 | 81 | 66.7% | 38.2% |
| 2018 | 95 | 60.0% | 38.3% |
| 2019 | 55 | 63.6% | 36.1% |
| 2020 | 48 | 52.1% | 31.8% |
| 2021 | 123 | 61.0% | 33.1% |
| 2022 | 133 | 30.8% | 31.6% |
| 2023 | 80 | 65.0% | 34.6% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Lyon County, State data
Minnesota's own radon test data
MeasuredWhat Minnesota's own agencies publish about radon tests in Lyon County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What the Minnesota Department of Health reports for Lyon County
Radon Testing (MN Public Health Data Access Portal): home radon tests reported voluntarily by private laboratories and licensed radon measurement professionals, counted by property. Period: 2016-2025.
Share with one or more tests at or above 4 pCi/L
63.7%
738 properties tested with one or more tests at or above 4 pCi/L
Median result
5.3 pCi/L
Average result
7.0 pCi/L
Tests behind these figures
116 properties tested a year on average
- MDH says these data do not include all of the radon tests conducted in Minnesota.
- Post-mitigation tests are excluded from the averages and the median; the percentages use each property's highest test.
- Each home is unique and can have very different results than a neighbor's home; the only way to know is to test.
- These figures describe tests reported to the Minnesota Department of Health in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.
Measured: Minnesota Department of Health data, 2016-2025.
Lyon County, Geology
The ground under Lyon County
PredictedUSGS's geologic map puts all of Lyon County's mapped land in one class: high radon potential. All of it lies in the area the map calls Central Lowland-Till Prairie, 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 |
|---|---|---|---|---|
| Central Lowland-Till Prairie | Silty and clayey till derived from shale and sandstone. | 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.
Lyon County beside the ground around it
Lyon County has more high-potential ground than Minnesota as a whole: 100% of its land against 61.1%. Of the 5 counties that border it, none has as large a share of high-potential ground; Lincoln County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Lyon County, Local resources
Radon testing and mitigation in Lyon County
Listed radon businesses with an address in Lyon County:
- MDH Indoor Air UnitMDH Indoor Air Unit, run by MN Dept. of Health, licenses or certifies radon professionals and states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in Minnesota.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- Professionals in Minnesota255 professionals are listed in Minnesota.
Listed radon professionals by town: Marshall, Minneota, Balaton, Lynd
What Minnesota's program says
- Phone
- 651-201-4601
- health.indoorair@state.mn.us
- Licensing of radon professionals
The Radon Licensing Act requires anyone who performs a radon test or radon mitigation, in a building they do not own or lease, must be licensed by MDH.
- Disclosure when a home is sold or rented
The Minnesota Radon Awareness Act requires specific disclosure and education be provided to potential home buyers during residential real estate transactions in Minnesota.
What it means
Lyon County, Questions
Questions about radon in Lyon County
Are radon levels high in Lyon County?
In 2023, 65.0% of the radon tests reported to CDC for Lyon County, Minnesota were at or above 4 pCi/L, and the median reported pre-mitigation result was 6.1 pCi/L. Of 62 Minnesota counties with 30 or more tests for the same period, 5 reported a higher share; pooled, the state comes to 34.6%.
Which counties border Lyon County?
Lyon County borders 5 counties: Lincoln County, Murray County, Yellow Medicine County, Redwood County and Pipestone County.
Products
Lyon County, Products
Testing a home in Lyon County
In Lyon County, 65.0% of 80 tests reported to CDC in 2023 reached 4 pCi/L, against 34.6% pooled across Minnesota. In Zone 1 the year-round level in Lyon 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
MonitorAEGTEST
HOUND-3786 rechargeable radon monitor with a 3.5-inch color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Ion chamber
First reading: Within 10 minutes
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Lyon County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Lyon County
Explore
Lyon County, Bordering counties
Counties bordering Lyon County
Calculated by Radon411- Radon levels in Yellow Medicine CountyEPA zone 1
73.7%at or above 4 pCi/L
Median 7.8 pCi/L · 19 tests · 8.7 points above Lyon County
- Radon levels in Murray CountyEPA zone 1
72.0%at or above 4 pCi/L
Median 8.1 pCi/L · 25 tests · 7.0 points above Lyon County
- Radon levels in Pipestone CountyEPA zone 1
71.4%at or above 4 pCi/L
Median 7.3 pCi/L · 28 tests · 6.4 points above Lyon County
- Radon levels in Redwood CountyEPA zone 1
54.8%at or above 4 pCi/L
Median 4.6 pCi/L · 31 tests · 10.2 points below Lyon County
- Radon levels in Lincoln CountyEPA zone 1
54.2%at or above 4 pCi/L
Median 5.0 pCi/L · 24 tests · 10.8 points below Lyon County
Lyon County, Cities and towns
Cities and towns in Lyon County
The Census Bureau estimates 25,684 residents in Lyon County for July 1, 2025, 255 more than in 2020 (+1.0%). That works out to 36 people per square mile of land. Marshall alone is home to 14,171 of them, 55.2% of the total. Together its 11 incorporated places hold 80.6% of those residents; the other 19.4% live outside any of them. CDC's 80 reported tests for 2023 work out to 3.1 per 1,000 residents (2025 estimate), close to Minnesota's 3.9.
From Marshall to Florence, CDC publishes no figure by town: each reads Lyon County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Marshall | 14,171 | +2.3% | 55.2% |
| Tracy | 2,039 | −1.2% | 7.9% |
| Minneota | 1,357 | −0.7% | 5.3% |
| Cottonwood | 1,138 | −0.6% | 4.4% |
| Balaton | 578 | −1.9% | 2.3% |
| Lynd | 428 | −0.9% | 1.7% |
| Ghent | 376 | +0.3% | 1.5% |
| Russell | 356 | +2.6% | 1.4% |
| Taunton | 130 | −3.0% | 0.5% |
| Garvin | 117 | −2.5% | 0.5% |
| Florence | 21 | Level | Under 0.1% |
11 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).
Lyon County, Homes
Homes in Lyon County
Of Lyon County's 11,252 homes, 73% are detached houses, against 66% across Minnesota; 15% are in buildings of five or more homes. Half of its homes were built before 1971, close to Minnesota's 1978: 35% date from before 1960 and 14% from 2000 or later. 71% of occupied homes are lived in by their owner (Minnesota: 72%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Lyon County | Minnesota |
|---|---|---|
| Housing units | 11,252 | 2,519,538 |
| Detached houses | 73% | 66% |
| In buildings of 5 or more | 15% | 19% |
| Mobile homes | 2% | 3% |
| Built before 1960 | 35% | 29% |
| Built since 2000 | 14% | 22% |
| Middle year built | 1971 | 1978 |
| Owner-occupied | 71% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.