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
Locations and reports
Radon Levels in Jefferson County, Pennsylvania
EPA puts Jefferson County in Zone 2, its middle radon zone, and 38.6% of its 254 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
38.6%
8.3 pts above PA
- Jefferson
- 38.6%
- PA
- 30.3%
254 tests, 2020
Median result
2.6pCi/L
Below action level
- Jefferson
- 2.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2020
Tests reported
254
40th of 63 by tests
- Jefferson
- 254
- 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
36 of 63
Middle half
- Jefferson
- 38.6%
- Perry
- 57.7%
By share, of 63 with 30+ tests
Read a result for Jefferson County
Starts at Jefferson County's median, 2.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.6 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. Jefferson County's median reported result, 2020.
The data
Jefferson County, At a glance
Jefferson County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Jefferson County is a
USGS geologic potential: Moderate across 64% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Jefferson County, 2020
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 60.4% |
| 2015 | 53.3% |
| 2016 | 50.4% |
| 2017 | 63.1% |
| 2018 | 53.7% |
| 2019 | 57.0% |
| 2020 | 38.6% |
2020: 38.6%. Across these years the share ran from 38.6% to 63.1%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 254 tests reported to CDC for Jefferson 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).
Jefferson County, Compared
Jefferson County radon figures, compared
Calculated by Radon411In Jefferson County, about 4 in 10 reported tests in 2020 (98 of 254) were at or above EPA's action level. Against the national pool of 25.5%, the gap is 13.1 points higher. Across 67 Pennsylvania counties pooled together, 30.3% of tests reached that level, so Jefferson County runs 8.3 points above its state.
Of 5 neighbours with a figure, 4 reported a larger share at or above 4 pCi/L and 1 a smaller one; the spread is 31.8% (Clarion County) to 47.6% (Armstrong County). By share, Jefferson County is 36th of 63 Pennsylvania counties with 30 or more tests for the same period.
Year by year, 2014 opened at 60.4% and 2020 closed at 38.6% (down 21.8 points), with 2017 the high at 63.1%. Half the tests came in under 2.6 pCi/L and half over it; the single highest reached 54.5 pCi/L. Below the action level, 100 tests (39.4%) came in under 2 pCi/L, against 44.3% statewide, and 56 tests (22.0%) 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 38.6% share point the same way here. USGS geology rates 64% of the county's land moderate radon potential.
The busiest year on file was 2015, with 492 tests reported; the quietest, 2018, had 205.
Jefferson CountyPennsylvania, pooled
38.6% % of tests30.3% % of tests
| Year | Tests | Jefferson County, at or above 4 pCi/L | Pennsylvania, pooled |
|---|---|---|---|
| 2014 | 217 | 60.4% | 36.1% |
| 2015 | 492 | 53.3% | 37.8% |
| 2016 | 244 | 50.4% | 34.4% |
| 2017 | 271 | 63.1% | 35.1% |
| 2018 | 205 | 53.7% | 30.5% |
| 2019 | 207 | 57.0% | 31.4% |
| 2020 | 254 | 38.6% | 30.3% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Jefferson County, State data
Pennsylvania's own radon test data
MeasuredWhat Pennsylvania's own agencies publish about radon tests in Jefferson 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 Jefferson County
Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 29 ZIP codes that lie wholly or partly in Jefferson County, each with the state's own figures for it. Period: Period not stated by DEP.
| ZIP code | What the state reports |
|---|---|
| 15711 | Basement: figures not shown; First floor: figures not shown |
| 15715 | Basement: figures not shown; First floor: figures not shown |
| 15730 | Basement: figures not shown |
| 15733 | Basement: figures not shown; First floor: figures not shown |
| 15764 | Basement: figures not shown |
| 15767 | Basement: average 13.4 pCi/L, 843 tests; First floor: average 7.6 pCi/L, 111 tests |
| 15770 | Basement: figures not shown |
| 15772 | Basement: average 8.3 pCi/L, 46 tests; First floor: figures not shown |
| 15776 | Basement: figures not shown; First floor: figures not shown |
| 15778 | Basement: figures not shown |
| 15780 | Basement: figures not shown |
| 15781 | Basement: figures not shown |
| 15784 | Basement: figures not shown; First floor: figures not shown |
| 15801 | Basement: average 10.9 pCi/L, 4,275 tests; First floor: average 5.6 pCi/L, 270 tests |
| 15823 | Basement: average 4.9 pCi/L, 59 tests; First floor: figures not shown |
| 15824 | Basement: average 8.4 pCi/L, 318 tests; First floor: average 4.3 pCi/L, 31 tests |
| 15825 | Basement: average 9.3 pCi/L, 628 tests; First floor: average 5.5 pCi/L, 88 tests |
| 15828 | Basement: figures not shown; First floor: figures not shown |
| 15829 | Basement: average 9.2 pCi/L, 46 tests; First floor: figures not shown |
| 15840 | Basement: average 8.1 pCi/L, 122 tests; First floor: figures not shown |
| 15847 | Basement: figures not shown |
| 15851 | Basement: average 10.3 pCi/L, 236 tests; First floor: average 4.6 pCi/L, 39 tests |
| 15853 | Basement: average 5.9 pCi/L, 341 tests; First floor: average 8.3 pCi/L, 55 tests |
| 15860 | Basement: figures not shown; First floor: figures not shown |
| 15863 | Basement: figures not shown; First floor: figures not shown |
| 15864 | Basement: average 9.8 pCi/L, 50 tests; First floor: figures not shown |
| 15865 | Basement: average 9.0 pCi/L, 67 tests; First floor: figures not shown |
| 16222 | Basement: average 11.9 pCi/L, 47 tests; First floor: figures not shown |
| 16240 | Basement: figures not shown; First floor: figures not shown |
- 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.
Jefferson County, Geology
The ground under Jefferson County
PredictedUSGS's geologic map splits Jefferson County: 63.7% of its land is moderate radon potential and 36.3% high. The map puts 63.7% of Jefferson County in the area it calls High Plateau and 33.9% in Pennsylvanian Rocks of the Pittsburgh Low Plateau, with one smaller area beside them. USGS gives the first a radon index of 10, in the moderate band (9 to 11), and the second 14, in the high band (12 to 17).
| 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 | 63.7% |
| Pennsylvanian Rocks of the Pittsburgh Low Plateau | Pennsylvanian marine shale, siltstone, sandstone, limestone, and coal. | High | 14 | 33.9% |
| Mountainous High Plateau | Sandstone, shale and conglomerate. | High | 12 | 2.4% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Jefferson County beside the ground around it
Pennsylvania as a whole has more high-potential ground than Jefferson County: 70.4% of its land, against 36.3% here. Of the 6 counties that border it, 4 have more high-potential ground, Armstrong County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Jefferson County, Local resources
Radon testing and mitigation in Jefferson 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
Jefferson County, Questions
Questions about radon in Jefferson County
Are radon levels high in Jefferson County?
In 2020, 38.6% of the radon tests reported to CDC for Jefferson County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.6 pCi/L. Of 63 Pennsylvania counties with 30 or more tests for the same period, 35 reported a higher share; pooled, the state comes to 30.3%.
Which counties border Jefferson County?
Jefferson County borders 6 counties: Elk County, Clarion County, Forest County, Clearfield County, Armstrong County and Indiana County.
Products
Jefferson County, Products
Testing a home in Jefferson County
In Jefferson County, 38.6% of 254 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 Jefferson County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorX-Sense
XR0B-SR battery digital radon monitor with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Jefferson County, Bordering counties
Counties bordering Jefferson County
Calculated by Radon411- Radon levels in Forest CountyEPA zone 2
56.3%at or above 4 pCi/L
Median 5.0 pCi/L · 16 tests · 17.7 points above Jefferson County
- Radon levels in Armstrong CountyEPA zone 1
47.6%at or above 4 pCi/L
Median 3.7 pCi/L · 187 tests · 9.0 points above Jefferson County
- Radon levels in Clearfield CountyEPA zone 1
47.5%at or above 4 pCi/L
Median 3.6 pCi/L · 394 tests · 8.9 points above Jefferson County
- Radon levels in Elk CountyEPA zone 2
47.0%at or above 4 pCi/L
Median 3.5 pCi/L · 66 tests · 8.4 points above Jefferson County
- Radon levels in Indiana CountyEPA zone 1
44.3%at or above 4 pCi/L
Median 3.6 pCi/L · 228 tests · 5.7 points above Jefferson County
- Radon levels in Clarion CountyEPA zone 1
31.8%at or above 4 pCi/L
Median 2.9 pCi/L · 107 tests · 6.8 points below Jefferson County
Jefferson County, Cities and towns
Cities and towns in Jefferson County
About 43,255 people live in Jefferson County by the Census Bureau's estimate for July 1, 2025, 1,233 fewer than in 2020 (−2.8%). That works out to 66 people per square mile of land. No town dominates: Punxsutawney, the largest, has 5,558 residents, 12.8% of the total. CDC's 254 reported tests for 2020 work out to 5.9 per 1,000 residents (2025 estimate), close to Pennsylvania's 7.2.
From Punxsutawney to Worthville, CDC publishes no figure by town: each reads Jefferson County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Punxsutawney | 5,558 | −3.6% | 12.8% |
| Brookville | 3,883 | −2.8% | 9.0% |
| Reynoldsville | 2,473 | −2.9% | 5.7% |
| Brockway | 2,213 | −2.9% | 5.1% |
| Sykesville | 1,078 | −3.0% | 2.5% |
| Falls Creekextends beyond Jefferson County | 1,002 | −2.8% | Counted whole |
| Big Run | 622 | −2.7% | 1.4% |
| Summerville | 496 | −2.9% | 1.1% |
| Corsica | 312 | −2.2% | 0.7% |
| Timblin | 140 | −3.4% | 0.3% |
| Worthville | 72 | −2.7% | 0.2% |
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). A place that extends beyond Jefferson County is counted whole, so it has no share.
Jefferson County, Homes
Homes in Jefferson County
Jefferson County is a place of houses on their own lots: 78% of its 22,053 homes are detached single-family houses, against 57% across Pennsylvania. Half of its homes were built before 1962, close to Pennsylvania's 1965: 48% date from before 1960 and 11% from 2000 or later. 74% of occupied homes are lived in by their owner (Pennsylvania: 69%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Jefferson County | Pennsylvania |
|---|---|---|
| Housing units | 22,053 | 5,779,663 |
| Detached houses | 78% | 57% |
| In buildings of 5 or more | 5% | 13% |
| Mobile homes | 8% | 4% |
| Built before 1960 | 48% | 45% |
| Built since 2000 | 11% | 14% |
| Middle year built | 1962 | 1965 |
| Owner-occupied | 74% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.