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 Sedgwick County, Colorado
EPA puts Sedgwick County in Zone 1, its highest radon zone, and only 1 radon test from it is on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
58.8%
Logan County
- Logan
- 58.8%
- Phillips
- 40.7%
5 of 5 neighbours have 30+ tests, 2008 to 2017
Nearest county
40.7%
Phillips County, 19 miles
- Phillips
- 40.7%
- Colorado
- 47.0%
Share at 4+ pCi/L, 54 tests, 2008 to 2017
Ground above low
100.0%
Level with Colorado
- Sedgwick
- 100.0%
- Colorado
- 100.0%
Share of land USGS rates moderate or high potential
Tests reported
18
Too few for a share
- Sedgwick
- 18
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Read a result for Sedgwick County
Starts at EPA's action level
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.
The data
Sedgwick County, At a glance
Sedgwick County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Sedgwick County in
USGS geologic potential: High across 79% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Sedgwick County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2015 | 50.0% |
| 2017 | 0.0% |
| 2018 | 57.1% |
| 2019 | 8.3% |
| 2020 | 0.0% |
| 2021 | 100.0% |
| 2022 | 50.0% |
| 2023 | 100.0% |
2023: 100.0%. Across these years the share ran from 0.0% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 1 test was reported to CDC for Sedgwick 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).
Sedgwick County, Compared
Sedgwick County radon figures, compared
Calculated by Radon411CDC's largest figure for Sedgwick County rests on 18 tests over the 2008 to 2017 laboratory totals, 8 of them at or above 4 pCi/L, so each test moves its share by 5.6 points and no rank or comparison is drawn from it. Results reached as high as 10.4 pCi/L, with a middle value of 3.8 pCi/L.
Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Logan County reported the largest share at or above 4 pCi/L, 58.8%, and Phillips County the smallest, 40.7%, with Cheyenne County, NE at 53.4%, Perkins County, NE at 50.0% and Deuel County, NE at 42.9% between. Farther out, Yuma County (60 miles away) at 57.1%, Washington County (77 miles away) at 62.8% and Morgan County (88 miles away) at 59.1% have figures too. Pooled across 63 Colorado counties, 47.0% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Kit Carson County reported the highest share (71.4%) and Alamosa County the lowest (26.6%). EPA's 1993 map puts Sedgwick County in Zone 1, the map's highest label: a predicted county average above 4 pCi/L. USGS geology rates 79% of the county's land high radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Sedgwick County, State data
Colorado's own radon test data
MeasuredWhat Colorado's own agencies publish about radon tests in Sedgwick County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What Colorado CDPHE reports for Sedgwick County
Radon data (county results): radon test results received from radon testing labs, primarily short-term household tests taken by the homeowner. Period: 2005-2025.
Share over 4 pCi/L
21.3%
19 of 89 tests
Median result
1.9 pCi/L
Highest result
11.7 pCi/L
Tests behind these figures
89 tests
- CDPHE says these data do not give actual radon levels in homes that have not been tested.
- When possible, only tests conducted before a mitigation system was installed are used.
- Some counties have very small numbers of test results, and their summaries may be less representative.
- These figures describe tests reported to Colorado CDPHE in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.
Measured: Colorado CDPHE data, 2005-2025.
Sedgwick County, Geology
The ground under Sedgwick County
PredictedMost of the ground under Sedgwick County is one class on USGS's geologic map: 78.5% of its land is high radon potential, with 21.5% moderate. The map puts 71.0% of Sedgwick County in the area it calls Ogallala Formation and 21.5% in White River Formation, with one smaller area beside them. USGS gives the first a radon index of 12, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Ogallala Formation | Tertiary sandstone, in part covered by windblown eolian sand and loess deposits. | High | 12 | 71.0% |
| White River Formation | Siltstone, sandstone, conglomerate, volcanic tuff. | Moderate | 11 | 21.5% |
| High Plains | Quaternary deposits and Cretaceous marine shales that locally have a high radiometric signature. | High | 12 | 7.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Sedgwick County beside the ground around it
On high-potential ground Sedgwick County is close to Colorado as a whole: 78.5% of its land against 74.8%. Of the 5 counties that border it, 1 has more high-potential ground, Phillips County the most at 88.1%.
The map rates the ground, not the air in any home.
Local help
Sedgwick County, Local resources
Radon testing and mitigation in Sedgwick County
- Colorado's radon programColorado Department of Public Health and EnvironmentColorado's radon program 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 Colorado.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Order a discounted radon test kit
- Compare kits
- Professionals in Colorado25 professionals are listed in Colorado.
What Colorado's program says
- Licensing of radon professionals
Listed contractors are certified by the National Radon Proficiency Program or the National Radon Safety Board, and must be licensed by the Colorado Department of Regulatory Agencies.
- Disclosure when a home is sold or rented
As of August 7, 2023, landlords in Colorado are required to disclose radon information when a tenant signs a lease agreement.
What it means
Sedgwick County, Questions
Questions about radon in Sedgwick County
Are radon levels high in Sedgwick County?
In 2023, 100.0% of the radon tests reported to CDC for Sedgwick County, Colorado were at or above 4 pCi/L, and the median reported pre-mitigation result was 11.7 pCi/L. Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Logan County reported the largest share at or above 4 pCi/L, 58.8%, and Phillips County the smallest, 40.7%, with Cheyenne County, NE at 53.4%, Perkins County, NE at 50.0% and Deuel County, NE at 42.9% between.
Which counties border Sedgwick County?
Sedgwick County borders 5 counties: Deuel County, NE, Phillips County, CO, Perkins County, NE, Cheyenne County, NE and Logan County, CO.
Products
Sedgwick County, Products
Testing a home in Sedgwick County
No CDC figure names Sedgwick County; the nearest county with one, Phillips County (19 miles away), reported 40.7% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. In Zone 1 the year-round level in Sedgwick 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 monitorMonitorSafetySiren
Pro4 plug-in radon detector with a display and alarm
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
First reading: Within 48 hours
Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Sedgwick County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Sedgwick County
Explore
Sedgwick County, Bordering counties
Counties bordering Sedgwick County
Calculated by Radon411- Radon levels in Logan County, COEPA zone 1
58.8%at or above 4 pCi/L
Median 4.8 pCi/L · 80 tests
- Radon levels in Cheyenne County, NEEPA zone 2
53.4%at or above 4 pCi/L
Median 4.1 pCi/L · 292 tests
- Radon levels in Perkins County, NEEPA zone 2
50.0%at or above 4 pCi/L
Median 4.0 pCi/L · 40 tests
- Radon levels in Deuel County, NEEPA zone 2
42.9%at or above 4 pCi/L
Median 3.5 pCi/L · 49 tests
- Radon levels in Phillips County, COEPA zone 1
40.7%at or above 4 pCi/L
Median 3.5 pCi/L · 54 tests
Sedgwick County, Cities and towns
Cities and towns in Sedgwick County
Sedgwick County has been losing residents: from 2,391 in 2020 to 2,247 on July 1, 2025, a fall of 6.0% by the Census Bureau's estimates. Spread over its land, that is 4.1 people to the square mile. Julesburg alone is home to 1,217 of them, 54.2% of the total. Together its 3 incorporated places hold 72.8% of those residents; the other 27.2% live outside any of them. Reported testing is thin here: 18 tests over 2008 to 2017, or 8.0 for every 1,000 residents (2025 estimate), where Colorado as a whole comes to 16.0.
From Julesburg to Sedgwick, CDC publishes no figure by town: each reads Sedgwick County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Julesburg | 1,217 | −6.3% | 54.2% |
| Ovid | 256 | −5.2% | 11.4% |
| Sedgwick | 162 | −6.4% | 7.2% |
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).
Sedgwick County, Homes
Homes in Sedgwick County
Sedgwick County is a place of houses on their own lots: 82% of its 1,184 homes are detached single-family houses, against 62% across Colorado. The homes are older than Colorado's as a whole: half were built before 1953 (1987 for Colorado), and 60% date from before 1960. 72% of occupied homes are lived in by their owner (Colorado: 66%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Sedgwick County | Colorado |
|---|---|---|
| Housing units | 1,184 | 2,545,124 |
| Detached houses | 82% | 62% |
| In buildings of 5 or more | 8% | 22% |
| Mobile homes | 2% | 4% |
| Built before 1960 | 60% | 16% |
| Built since 2000 | 5% | 31% |
| Middle year built | 1953 | 1987 |
| Owner-occupied | 72% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.