Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
Locations and reports
Radon Levels in Warren County, Pennsylvania
EPA puts Warren County in Zone 2, its middle radon zone, and 38.7% of its 119 reported radon tests (2020) 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
38.7%
8.4 pts above PA
- Warren
- 38.7%
- PA
- 30.3%
119 tests, 2020
Median result
2.8pCi/L
Below action level
- Warren
- 2.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2020
Tests reported
119
53rd of 63 by tests
- Warren
- 119
- Montgomery
- 10,508
Reported to CDC before any fix, 2020
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in PA
35 of 63
Middle half
- Warren
- 38.7%
- Perry
- 57.7%
By share, of 63 with 30+ tests
Read a result for Warren County
Starts at Warren County's median, 2.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.8 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, 2020.
The data
Warren County, At a glance
Warren County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Warren County is a
USGS geologic potential: Moderate across 97% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Warren County, 2020
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 49.2% |
| 2015 | 41.6% |
| 2016 | 44.7% |
| 2017 | 46.2% |
| 2018 | 38.9% |
| 2019 | 51.2% |
| 2020 | 38.7% |
2020: 38.7%. Across these years the share ran from 38.7% to 51.2%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 119 tests reported to CDC for Warren County over 2020, 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: 2020. Measured data period: 2005 to 2020 (every CDC figure on file).
Warren County, Compared
Warren County radon figures, compared
Calculated by Radon411In Warren County, about 4 in 10 reported tests in 2020 (46 of 119) were at or above EPA's action level. Against the national pool of 25.5%, the gap is 13.2 points higher. Across 67 Pennsylvania counties pooled together, 30.3% of tests reached that level, so Warren County runs 8.4 points above its state.
Of 4 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 22.2% (Erie County) to 47.0% (Elk County). By share, Warren County is 35th of 63 Pennsylvania counties with 30 or more tests for the same period.
Year by year, 2014 opened at 49.2% and 2020 closed at 38.7% (down 10.5 points), with 2019 the high at 51.2%. Half the tests came in under 2.8 pCi/L and half over it; the single highest reached 68.7 pCi/L. Below the action level, 48 tests (40.3%) came in under 2 pCi/L, against 44.3% statewide, and 25 tests (21.0%) fell between 2 and 4, against 25.4% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 38.7% share point the same way here. USGS geology rates 97% of the county's land moderate radon potential.
The busiest year on file was 2019, with 121 tests reported; the quietest, 2014, had 59.
Warren CountyPennsylvania, pooled
38.7% % of tests30.3% % of tests
| Year | Tests | Warren County, at or above 4 pCi/L | Pennsylvania, pooled |
|---|---|---|---|
| 2014 | 59 | 49.2% | 36.1% |
| 2015 | 77 | 41.6% | 37.8% |
| 2016 | 114 | 44.7% | 34.4% |
| 2017 | 119 | 46.2% | 35.1% |
| 2018 | 108 | 38.9% | 30.5% |
| 2019 | 121 | 51.2% | 31.4% |
| 2020 | 119 | 38.7% | 30.3% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Warren County, State data
Pennsylvania's own radon test data
MeasuredWhat Pennsylvania's own agencies publish about radon tests in Warren County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What Pennsylvania DEP reports for the ZIP codes in Warren County
Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 20 ZIP codes that lie wholly or partly in Warren County, each with the state's own figures for it. Period: Period not stated by DEP.
| ZIP code | What the state reports |
|---|---|
| 16312 | First floor: figures not shown |
| 16313 | Basement: average 11.7 pCi/L, 32 tests; First floor: figures not shown |
| 16329 | Basement: figures not shown; First floor: figures not shown |
| 16340 | Basement: average 7.9 pCi/L, 49 tests; First floor: figures not shown |
| 16345 | Basement: average 11.4 pCi/L, 571 tests; First floor: average 7.9 pCi/L, 72 tests |
| 16347 | Basement: average 5.3 pCi/L, 42 tests; First floor: figures not shown |
| 16350 | Basement: average 6.3 pCi/L, 51 tests; First floor: figures not shown |
| 16351 | Basement: average 6.2 pCi/L, 33 tests; First floor: figures not shown |
| 16352 | Basement: figures not shown; First floor: figures not shown |
| 16354 | Basement: average 9.7 pCi/L, 297 tests; First floor: average 4.6 pCi/L, 53 tests |
| 16365 | Basement: average 6.7 pCi/L, 1,716 tests; First floor: average 4.2 pCi/L, 296 tests |
| 16371 | Basement: average 8.9 pCi/L, 121 tests; First floor: figures not shown |
| 16402 | Basement: figures not shown; First floor: figures not shown |
| 16405 | Basement: figures not shown; First floor: figures not shown |
| 16407 | Basement: average 5.5 pCi/L, 695 tests; First floor: average 3.0 pCi/L, 102 tests |
| 16416 | Basement: figures not shown |
| 16420 | Basement: figures not shown; First floor: figures not shown |
| 16434 | Basement: figures not shown; First floor: figures not shown |
| 16436 | Basement: figures not shown; First floor: figures not shown |
| 16701 | Basement: average 14.3 pCi/L, 412 tests; First floor: average 1.2 pCi/L, 89 tests |
- DEP's report gives the number of tests, the highest result and the average result for each floor tested; it states no period.
- DEP says the smartest thing to do is to test your home for radon, no matter where you live.
- A ZIP code that crosses the county line is listed whole; its figures cover all of it.
Measured: Pennsylvania DEP data, Period not stated by DEP.
Warren County, Geology
The ground under Warren County
PredictedMost of the ground under Warren County is one class on USGS's geologic map: 96.6% of its land is moderate radon potential, with 3.4% high. The map puts 71.4% of Warren County in the area it calls High Plateau and 25.2% in Glaciated Pittsburgh Plateau, with one smaller area beside them. USGS gives the first a radon index of 10 and the second 11, both in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| High Plateau | Marine and continental Devonian-Pennsylvanian shale, sandstone, limestone, siltstone, and coal. | Moderate | 10 | 71.4% |
| Glaciated Pittsburgh Plateau | Late-Wisconsin till overlying sandstone, shale, limestone, and coal. | Moderate | 11 | 25.2% |
| Pennsylvanian Rocks of the Pittsburgh Low Plateau | Pennsylvanian marine shale, siltstone, sandstone, limestone, and coal. | High | 14 | 3.3% |
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
Pennsylvania as a whole has more high-potential ground than Warren County: 70.4% of its land, against 3.4% here. Of the 8 counties that border it, 6 have more high-potential ground, Chautauqua County, NY the most at 99.9%.
The map rates the ground, not the air in any home.
Local help
Warren County, Local resources
Radon testing and mitigation in Warren County
- Radon DivisionRadon Division, run by Department of Environmental Protection, licenses or certifies radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Pennsylvania.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Through an EPA-funded program, hospitals give parents of newborn children a packet of information which includes a coupon for a free radon test kit from the DEP.
- Compare kits
- Professionals in Pennsylvania151 professionals are listed in Pennsylvania.
What Pennsylvania's program says
- Phone
- 800-237-2366
- Licensing of radon professionals
The Radon Certification Act requires DEP to establish by regulation, a certification program for persons conducting radon gas and radon progeny testing, laboratory analysis and mitigation of radon contamination in buildings.
What it means
Warren County, Questions
Questions about radon in Warren County
Are radon levels high in Warren County?
In 2020, 38.7% of the radon tests reported to CDC for Warren County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.8 pCi/L. Of 63 Pennsylvania counties with 30 or more tests for the same period, 34 reported a higher share; pooled, the state comes to 30.3%.
Which counties border Warren County?
Warren County borders 8 counties: Forest County, PA, Venango County, PA, Elk County, PA, McKean County, PA, Chautauqua County, NY, Crawford County, PA, Erie County, PA and Cattaraugus County, NY.
Products
Warren County, Products
Testing a home in Warren County
In Warren County, 38.7% of 119 tests reported to CDC in 2020 reached 4 pCi/L, against 30.3% pooled across Pennsylvania. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Warren County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
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
MonitorSafetySiren
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
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Warren County, Bordering counties
Counties bordering Warren County
Calculated by Radon411- Radon levels in Forest County, PAEPA zone 2
56.3%at or above 4 pCi/L
Median 5.0 pCi/L · 16 tests · 17.6 points above Warren County
- Radon levels in Chautauqua County, NYEPA zone 1
50.0%at or above 4 pCi/L
Median 3.2 pCi/L · 2 tests · 11.3 points above Warren County
- Radon levels in Elk County, PAEPA zone 2
47.0%at or above 4 pCi/L
Median 3.5 pCi/L · 66 tests · 8.3 points above Warren County
- Radon levels in Venango County, PAEPA zone 1
34.1%at or above 4 pCi/L
Median 3.0 pCi/L · 179 tests · 4.6 points below Warren County
- Radon levels in Crawford County, PAEPA zone 2
29.9%at or above 4 pCi/L
Median 2.6 pCi/L · 221 tests · 8.8 points below Warren County
- Radon levels in Erie County, PAEPA zone 2
22.2%at or above 4 pCi/L
Median 1.9 pCi/L · 1,162 tests · 16.5 points below Warren County
- Radon levels in Cattaraugus County, NYEPA zone 1
12.5%at or above 4 pCi/L
Median 2.4 pCi/L · 8 tests · 26.2 points below Warren County
- Radon levels in McKean County, PAEPA zone 2
10.5%at or above 4 pCi/L
Median 1.7 pCi/L · 19 tests · 28.2 points below Warren County
Warren County, Cities and towns
Cities and towns in Warren County
About 37,038 people live in Warren County by the Census Bureau's estimate for July 1, 2025, 1,475 fewer than in 2020 (−3.8%). That works out to 42 people per square mile of land. Its largest town, Warren, has 9,046 residents, 24.4% of the total. Together its 6 incorporated places hold 33.3% of those residents; the other 66.7% live outside any of them. Reported testing is thin here: 119 tests over 2020, or 3.2 for every 1,000 residents (2025 estimate), where Pennsylvania as a whole comes to 7.2.
From Warren to Bear Lake, CDC publishes no figure by town: each reads Warren County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Warren | 9,046 | −3.6% | 24.4% |
| Youngsville | 1,639 | −4.9% | 4.4% |
| Tidioute | 599 | −4.0% | 1.6% |
| Sugar Grove | 527 | −4.0% | 1.4% |
| Clarendon | 395 | −3.7% | 1.1% |
| Bear Lake | 141 | −4.7% | 0.4% |
6 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).
Warren County, Homes
Homes in Warren County
Warren County is a place of houses on their own lots: 78% of its 21,641 homes are detached single-family houses, against 57% across Pennsylvania. Half of its homes were built before 1961, close to Pennsylvania's 1965: 49% date from before 1960 and 8% from 2000 or later. Owners live in 78% of the occupied homes (Pennsylvania: 69%), so for most households a test and a fix are their own to order.
| Homes | Warren County | Pennsylvania |
|---|---|---|
| Housing units | 21,641 | 5,779,663 |
| Detached houses | 78% | 57% |
| In buildings of 5 or more | 5% | 13% |
| Mobile homes | 10% | 4% |
| Built before 1960 | 49% | 45% |
| Built since 2000 | 8% | 14% |
| Middle year built | 1961 | 1965 |
| Owner-occupied | 78% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.