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 Warren County, Virginia
EPA puts Warren County in Zone 1, its highest radon zone, and 36.9% of its 536 reported radon tests (2008 to 2017, laboratory totals) 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
36.9%
6.5 pts above VA
- Warren
- 36.9%
- Virginia
- 30.4%
536 tests, 2008 to 2017
Median result
2.7pCi/L
Below action level
- Warren
- 2.7 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
536
25th of 84 by tests
- Warren
- 536
- Fairfax
- 8,657
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 Virginia
37 of 84
Middle half
- Warren
- 36.9%
- Russell
- 67.3%
By share, of 84 with 30+ tests
Read a result for Warren County
Starts at Warren County's median, 2.7 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.7 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. Warren County's median reported result, 2008 to 2017.
The data
Warren County, At a glance
Warren County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Warren County in
USGS geologic potential: High across 53% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Warren County, 2008 to 2017, laboratory
Under 2 pCi/L: 36%2 to 4 pCi/L: 27%4 pCi/L and above: 37%
Of 536 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 195 | 36.4% |
| 2 to 4 pCi/L | 143 | 26.7% |
| 4 pCi/L and above | 198 | 36.9% |
What these figures count
These are the 536 tests reported to CDC for Warren 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).
Warren County, Compared
Warren County radon figures, compared
Calculated by Radon411In Warren County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (198 of 536) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 1.2 points higher. Across 131 Virginia counties pooled together, 30.4% of tests reached that level, so Warren County runs 6.5 points above its state.
Of 6 neighbours with a figure, 4 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 30.2% (Fauquier County) to 47.7% (Clarke County). By share, Warren County is 37th of 84 Virginia counties with 30 or more tests for the same period.
Half the tests came in under 2.7 pCi/L and half over it; the single highest reached 65.7 pCi/L. Below the action level, 195 tests (36.4%) came in under 2 pCi/L, against 44.7% statewide, and 143 tests (26.7%) fell between 2 and 4, against 24.9% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 36.9% share point the same way here. USGS geology rates 53% of the county's land high radon potential. CDC also counts 34 tests taken after mitigation in Warren County for the same period: tests in homes where a fix was already in.
CDC's ten-year totals for Warren County went from 364 tests (2005 to 2014) to 536 (2008 to 2017), the share going from 36.5% to 36.9%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Warren County, Geology
The ground under Warren County
PredictedUSGS's geologic map splits Warren County: 52.7% of its land is high radon potential and 47.3% moderate. The map puts 52.7% of Warren County in the area it calls Valley and Ridge and 47.3% in Blue Ridge. USGS gives the first a radon index of 15, in the high band (12 to 17), and the second 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Valley and Ridge | Cambrian dolomite, limestone, shale, and sandstone, Silurian-Ordovician limestone, dolomite, shale, and sandstone, Mississippian-Devonian sandstone, shale, limestone, gypsum, and coal. | High | 15 | 52.7% |
| Blue Ridge | Granite, pegmatite, monazite, schist, and gneiss. | Moderate | 10 | 47.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Warren County beside the ground around it
On high-potential ground Warren County is close to Virginia as a whole: 52.7% of its land against 47.9%. Of the 6 counties that border it, 4 have more high-potential ground, Frederick County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Warren County, Local resources
Radon testing and mitigation in Warren County
- VDH Radon ProgramVDH Radon Program answers questions about testing, mitigation and the rules in Virginia.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 Virginia2 professionals are listed in Virginia.
What Virginia's program says
- Phone
- (804) 864-8161
- Radon@vdh.virginia.gov
- Licensing of radon professionals
The Code of Virginia requires that Radon testers and mitigators be currently certified by either the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).
What it means
Warren County, Questions
Questions about radon in Warren County
Are radon levels high in Warren County?
Over the 2008 to 2017 laboratory totals, 36.9% of the radon tests reported to CDC for Warren County, Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.7 pCi/L. Of 84 Virginia counties with 30 or more tests for the same period, 36 reported a higher share; pooled, the state comes to 30.4%.
Which counties border Warren County?
Warren County borders 6 counties: Rappahannock County, Clarke County, Shenandoah County, Frederick County, Fauquier County and Page County.
Products
Warren County, Products
Testing a home in Warren County
In Warren County, 36.9% of 536 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.4% pooled across Virginia. In Zone 1 the year-round level in Warren 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
RadonScan-Plus USB-powered radon monitor with Wi-Fi
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 minutes
Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Warren County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Warren County
Explore
Warren County, Bordering counties
Counties bordering Warren County
Calculated by Radon411- Radon levels in Clarke CountyEPA zone 1
47.7%at or above 4 pCi/L
Median 3.5 pCi/L · 350 tests · 10.8 points above Warren County
- Radon levels in Frederick CountyEPA zone 1
44.1%at or above 4 pCi/L
Median 3.3 pCi/L · 2,451 tests · 7.2 points above Warren County
- Radon levels in Rappahannock CountyEPA zone 2
41.6%at or above 4 pCi/L
Median 3.3 pCi/L · 137 tests · 4.7 points above Warren County
- Radon levels in Page CountyEPA zone 1
38.3%at or above 4 pCi/L
Median 3.3 pCi/L · 141 tests · 1.4 points above Warren County
- Radon levels in Shenandoah CountyEPA zone 1
36.4%at or above 4 pCi/L
Median 2.7 pCi/L · 390 tests · 0.5 points below Warren County
- Radon levels in Fauquier CountyEPA zone 2
30.2%at or above 4 pCi/L
Median 2.5 pCi/L · 1,199 tests · 6.7 points below Warren County
Warren County, Cities and towns
Cities and towns in Warren County
The Census Bureau estimates 42,740 residents in Warren County for July 1, 2025, 1,944 more than in 2020 (+4.8%). That works out to 199 people per square mile of land. Front Royal, its one incorporated place, has 15,722 residents, 36.8% of the total. Testing is reported here more often than across the state: CDC's 536 reported tests for 2008 to 2017 come to 12.5 for every 1,000 residents (2025 estimate), against 6.0 for Virginia.
Front Royal is the one incorporated place here; CDC publishes no figure by town, so it reads Warren County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Front Royal | 15,722 | +4.6% | 36.8% |
One incorporated place, 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).
Warren County, Homes
Homes in Warren County
Warren County is a place of houses on their own lots: 84% of its 16,936 homes are detached single-family houses, against 61% across Virginia. Half of its homes were built before 1985, close to Virginia's 1984: 21% date from before 1960 and 23% from 2000 or later. Owners live in 76% of the occupied homes (Virginia: 67%), so for most households a test and a fix are their own to order.
| Homes | Warren County | Virginia |
|---|---|---|
| Housing units | 16,936 | 3,654,784 |
| Detached houses | 84% | 61% |
| In buildings of 5 or more | 5% | 19% |
| Mobile homes | 1% | 4% |
| Built before 1960 | 21% | 19% |
| Built since 2000 | 23% | 25% |
| Middle year built | 1985 | 1984 |
| Owner-occupied | 76% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.