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Radon Levels in York County, Pennsylvania

EPA puts York County in Zone 1, its highest radon zone, and high results are common there: 46.8% of the 3,679 radon tests reported to CDC (2020) 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    46.8%

    16.5 pts above PA

    York
    46.8%
    PA
    30.3%

    3,679 tests, 2020

  • Median result

    3.6pCi/L

    Below action level

    York
    3.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2020

  • Tests reported

    3,679

    8th of 63 by tests

    York
    3,679
    Montgomery
    10,508

    Reported to CDC before any fix, 2020

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in PA

    12 of 63

    Top quarter

    York
    46.8%
    Perry
    57.7%

    By share, of 63 with 30+ tests

Read a result for York County

Starts at York County's median, 3.6 pCi/L

3.6pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 3.6 pCi/L

Between 2 and 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 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. York County's median reported result, 2020.

Interpret this readingWhat a fix costs

The data

York County, At a glance

York County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of York County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

USGS geologic potential: High across 99% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for York County, 2020

Share of reported tests at or above 4 pCi/L, by year, York County
Share of reported tests at or above 4 pCi/L, by year, York County
YearShare of reported tests at or above 4 pCi/L
201454.4%
201554.7%
201650.6%
201753.2%
201850.3%
201946.4%
202046.8%

2020: 46.8%. Across these years the share ran from 46.4% to 54.7%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 3,679 tests reported to CDC for York 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).

How to read these figures

York County, Compared

York County radon figures, compared

Calculated by Radon411

In York County, about 5 in 10 reported tests in 2020 (1,723 of 3,679) were at or above EPA's action level. Against the national pool of 25.5%, the gap is 21.3 points higher. Across 67 Pennsylvania counties pooled together, 30.3% of tests reached that level, so York County runs 16.5 points above its state.

Of 4 neighbours with a figure, none reported a larger share at or above 4 pCi/L; the spread is 36.9% (Dauphin County) to 43.6% (Cumberland County). By share, York County is 12th of 63 Pennsylvania counties with 30 or more tests for the same period.

Year by year, 2014 opened at 54.4% and 2020 closed at 46.8% (down 7.6 points), with 2015 the high at 54.7%. Half the tests came in under 3.6 pCi/L and half over it; the single highest reached 547.0 pCi/L. Below the action level, 1,202 tests (32.7%) came in under 2 pCi/L, against 44.3% statewide, and 754 tests (20.5%) fell between 2 and 4, against 25.4% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 46.8% share point the same way here. USGS geology rates 99% of the county's land high radon potential.

The busiest year on file was 2015, with 3,972 tests reported; the quietest, 2014, had 2,734.

Share of reported tests at or above 4 pCi/L by year, York County against Pennsylvania2014 to 2020, years with 30 or more tests: York County 54.4% to 46.8%, the state's pooled share 30.3% in 2020.
York CountyPennsylvania, pooled
Share of reported tests at or above 4 pCi/L by year, York County against Pennsylvania: data table
YearTestsYork County, at or above 4 pCi/LPennsylvania, pooled
20142,73454.4%36.1%
20153,97254.7%37.8%
20163,84450.6%34.4%
20173,61053.2%35.1%
20183,47450.3%30.5%
20193,89846.4%31.4%
20203,67946.8%30.3%
York County against Pennsylvania, the United States and nearby counties, 2020
AreaTestsAt or above 4 pCi/LMedianDifference from York County
York County3,67946.8%3.6 pCi/LThis county
Pennsylvania, pooled67 counties, pooled93,66930.3%Not pooled−16.5 points
United States, pooled915 counties, pooled405,35525.5%Not pooled−21.3 points
Perry Countyhighest in the state18957.7%4.9 pCi/L+10.9 points
Philadelphia Countylowest in the state8,44210.6%1.7 pCi/L−36.2 points
Cumberland County, PAborders it2,95043.6%3.1 pCi/L−3.2 points
Lancaster County, PAborders it4,39843.3%3.0 pCi/L−3.5 points
Adams County, PAborders it85239.7%2.8 pCi/L−7.1 points
Dauphin County, PAborders it2,98636.9%2.0 pCi/L−9.9 points
Where York County's reported results fell, 2020, beside Pennsylvania and the United States
ResultYork County testsYork County sharePennsylvania shareU.S. shareAgainst Pennsylvania
Under 2 pCi/L1,20232.7%44.3%51.6%−11.6 points
2 to 4 pCi/L75420.5%25.4%22.9%−4.9 points
4 pCi/L and above1,72346.8%30.3%25.5%+16.5 points
York County ranked among the 63 Pennsylvania counties with 30 or more tests, by share at or above 4 pCi/L, 2020
CountyRankTestsAt or above 4 pCi/LMedian
Northumberland County7 of 6327549.8%3.9 pCi/L
Bedford County8 of 636947.8%3.8 pCi/L
Armstrong County9 of 6318747.6%3.7 pCi/L
Clearfield County10 of 6339447.5%3.6 pCi/L
Elk County11 of 636647.0%3.5 pCi/L
York County12 of 633,67946.8%3.6 pCi/L
Lycoming County13 of 6356245.2%3.5 pCi/L
Tioga County14 of 6316045.0%3.2 pCi/L
Cambria County15 of 6332944.7%3.3 pCi/L
Union County16 of 6318244.5%3.3 pCi/L
Indiana County17 of 6322844.3%3.6 pCi/L
York County radon tests by year, against Pennsylvania's pooled share
YearTestsAt or above 4 pCi/LMedianHighestPennsylvania, pooledChange from the row before
20203,67946.8%3.6 pCi/L547.0 pCi/L30.3%+0.4 points
20193,89846.4%3.6 pCi/L354.1 pCi/L31.4%−3.9 points
20183,47450.3%4.0 pCi/L772.5 pCi/L30.5%−2.9 points
20173,61053.2%4.4 pCi/L362.1 pCi/L35.1%+2.6 points
20163,84450.6%4.1 pCi/L279.1 pCi/L34.4%−4.1 points
20153,97254.7%4.6 pCi/L550.4 pCi/L37.8%+0.3 points
20142,73454.4%4.6 pCi/L521.8 pCi/L36.1%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

York County, State data

Pennsylvania's own radon test data

Measured

What Pennsylvania's own agencies publish about radon tests in York 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 York County

Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 47 ZIP codes that lie wholly or partly in York County, each with the state's own figures for it. Period: Period not stated by DEP.

ZIP codes in York County
ZIP codeWhat the state reports
17011Basement: average 8.5 pCi/L, 11,209 tests; First floor: average 5.5 pCi/L, 1,713 tests
17019Basement: average 7.6 pCi/L, 3,744 tests; First floor: average 3.7 pCi/L, 481 tests
17055Basement: average 11.9 pCi/L, 13,637 tests; First floor: average 7.1 pCi/L, 2,681 tests
17070Basement: average 8.5 pCi/L, 4,217 tests; First floor: average 5.6 pCi/L, 633 tests
17301Basement: average 4.5 pCi/L, 326 tests; First floor: figures not shown
17302Basement: average 18.7 pCi/L, 247 tests; First floor: figures not shown
17309Basement: average 23.6 pCi/L, 140 tests; First floor: figures not shown
17311Basement: figures not shown; First floor: figures not shown
17313Basement: average 16.7 pCi/L, 1,542 tests; First floor: average 11.6 pCi/L, 182 tests
17314Basement: average 11.6 pCi/L, 593 tests; First floor: average 5.9 pCi/L, 61 tests
17315Basement: average 7.4 pCi/L, 2,250 tests; First floor: average 3.7 pCi/L, 397 tests
17316Basement: average 5.3 pCi/L, 910 tests; First floor: average 2.6 pCi/L, 106 tests
17317Basement: figures not shown; First floor: figures not shown
17318Basement: figures not shown
17319Basement: average 7.0 pCi/L, 1,998 tests; First floor: average 4.7 pCi/L, 213 tests
17321Basement: average 12.7 pCi/L, 289 tests; First floor: figures not shown
17322Basement: average 20.8 pCi/L, 547 tests; First floor: average 6.4 pCi/L, 45 tests
17323Basement: figures not shown; First floor: figures not shown
17327Basement: average 17.4 pCi/L, 1,083 tests; First floor: average 7.5 pCi/L, 110 tests
17329Basement: average 24.0 pCi/L, 391 tests; First floor: figures not shown
17331Basement: average 11.0 pCi/L, 7,900 tests; First floor: average 5.7 pCi/L, 770 tests
17339Basement: average 7.4 pCi/L, 1,389 tests; First floor: average 4.1 pCi/L, 146 tests
17342Basement: average 20.3 pCi/L, 30 tests; First floor: figures not shown
17345Basement: average 7.0 pCi/L, 664 tests; First floor: average 5.0 pCi/L, 64 tests
17347Basement: average 13.3 pCi/L, 778 tests; First floor: average 6.1 pCi/L, 52 tests
17349Basement: average 9.4 pCi/L, 1,612 tests; First floor: average 6.8 pCi/L, 137 tests
17352Basement: average 12.7 pCi/L, 91 tests; First floor: figures not shown
17355Basement: figures not shown
17356Basement: average 16.3 pCi/L, 2,835 tests; First floor: average 7.2 pCi/L, 387 tests
17360Basement: average 16.3 pCi/L, 971 tests; First floor: average 13.2 pCi/L, 64 tests
17361Basement: average 9.0 pCi/L, 1,144 tests; First floor: average 6.0 pCi/L, 80 tests
17362Basement: average 21.0 pCi/L, 1,742 tests; First floor: average 9.3 pCi/L, 184 tests
17363Basement: average 15.1 pCi/L, 1,834 tests; First floor: average 8.7 pCi/L, 162 tests
17364Basement: average 8.7 pCi/L, 255 tests; First floor: average 4.0 pCi/L, 47 tests
17365Basement: average 5.0 pCi/L, 258 tests; First floor: average 1.4 pCi/L, 39 tests
17366Basement: average 17.9 pCi/L, 493 tests; First floor: average 12.5 pCi/L, 48 tests
17368Basement: average 23.0 pCi/L, 657 tests; First floor: average 8.2 pCi/L, 113 tests
17370Basement: average 6.8 pCi/L, 707 tests; First floor: average 3.8 pCi/L, 76 tests
17371Basement: figures not shown; First floor: figures not shown
17372Basement: average 9.1 pCi/L, 297 tests; First floor: average 2.8 pCi/L, 40 tests
17401Basement: average 4.3 pCi/L, 206 tests; First floor: average 1.9 pCi/L, 51 tests
17402Basement: average 11.7 pCi/L, 6,377 tests; First floor: average 6.4 pCi/L, 988 tests
17403Basement: average 12.3 pCi/L, 5,052 tests; First floor: average 9.0 pCi/L, 709 tests
17404Basement: average 7.7 pCi/L, 5,124 tests; First floor: average 4.4 pCi/L, 618 tests
17406Basement: average 13.5 pCi/L, 2,145 tests; First floor: average 4.8 pCi/L, 422 tests
17407Basement: average 16.8 pCi/L, 415 tests; First floor: average 5.1 pCi/L, 46 tests
17408Basement: average 10.0 pCi/L, 2,122 tests; First floor: average 6.2 pCi/L, 217 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.

York County, Geology

The ground under York County

Predicted

Most of the ground under York County is one class on USGS's geologic map: 99.2% of its land is high radon potential, with 0.7% low. The map puts 34.7% of York County in the area it calls Piedmiont Upland and 32.6% in Piedmont Lowland, with 2 smaller areas beside them. USGS gives both a radon index of 14, in the high band (12 to 17).

USGS's geologic areas under York County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Piedmiont UplandGranitic gneiss, graphitic gneiss, quartz monzonite, quartz monzonite gneiss, granodiorite, and granodiorite gneiss.High1434.7%
Piedmont LowlandMica schist, phyllite, hornblende gneiss, and marble.High1432.6%
Newark BasinGray shale and fluvial sandstone.High1231.8%
Blue Ridge Gettysburg BasinMetasedimentary and metavolcanic rocks.Low80.7%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

York County beside the ground around it

York County has more high-potential ground than Pennsylvania as a whole: 99.2% of its land against 70.4%. Of the 7 counties that border it, 2 have more high-potential ground, Dauphin County the most at 100%.

Share of land by USGS radon potential: York County, the 7 counties bordering it and Pennsylvania
AreaEPA zoneLow potentialModerate potentialHigh potential
York CountyZone 10.7%None99.2%
Adams CountyZone 127.7%None72.3%
Lancaster CountyZone 1NoneNone100%
Dauphin CountyZone 1NoneNone100%
Cumberland CountyZone 119.1%None80.9%
Carroll County, MDZone 1None14.3%85.7%
Baltimore County, MDZone 1None16.1%81.1%
Harford County, MDZone 1None26.7%70.2%
Pennsylvania67 counties, pooled by land areaVaries0.7%28.9%70.4%

The map rates the ground, not the air in any home.

Local help

York County, Local resources

Radon testing and mitigation in York County

Listed radon businesses with an address in York County:

Listed radon professionals by town: York

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

York County, Questions

Questions about radon in York County

Are radon levels high in York County?

In 2020, 46.8% of the radon tests reported to CDC for York County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.6 pCi/L. Of 63 Pennsylvania counties with 30 or more tests for the same period, 11 reported a higher share; pooled, the state comes to 30.3%.

Which counties border York County?

York County borders 7 counties: Adams County, PA, Lancaster County, PA, Dauphin County, PA, Cumberland County, PA, Carroll County, MD, Baltimore County, MD and Harford County, MD.

Products

York County, Products

Testing a home in York County

In York County, 46.8% of 3,679 tests reported to CDC in 2020 reached 4 pCi/L, against 30.3% pooled across Pennsylvania. In Zone 1 the year-round level in York 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

York County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like York County

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York County, Bordering counties

Counties bordering York County

Calculated by Radon411

York County, Cities and towns

Cities and towns in York County

The Census Bureau estimates 473,197 residents in York County for July 1, 2025, 16,472 more than in 2020 (+3.6%). That works out to 523 people per square mile of land. No town dominates: York, the largest, has 45,342 residents, 9.6% of the total. Together its 37 incorporated places hold 26.4% of those residents; the other 73.6% live outside any of them. CDC's 3,679 reported tests for 2020 work out to 7.8 per 1,000 residents (2025 estimate), close to Pennsylvania's 7.2.

From York to Yorkana, CDC publishes no figure by town: each reads York County's.

The 12 largest cities and towns in York County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
York45,342+1.2%9.6%
Hanover16,684+1.3%3.5%
Red Lion6,523+0.2%1.4%
New Freedom5,116+4.3%1.1%
West York5,110Level1.1%
Dallastown4,198Level0.9%
Shrewsbury4,014+4.4%0.8%
Manchester2,821+0.3%0.6%
Hallam2,798+0.9%0.6%
Dillsburg2,635+0.5%0.6%
Spring Grove2,520+6.3%0.5%
Wrightsville2,259+0.4%0.5%
  • North York
  • Stewartstown
  • Glen Rock
  • Dover
  • Jacobus
  • Loganville
  • Mount Wolf
  • Windsor
  • Yoe
  • East Prospect
  • Goldsboro
  • New Salem
  • Delta
  • York Haven
  • Jefferson
  • Winterstown
  • Franklintown
  • Cross Roads
  • Felton
  • Fawn Grove
  • Seven Valleys
  • Lewisberry
  • Wellsville
  • Railroad
The other 1 place in York County
  • Yorkana

37 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).

York County, Homes

Homes in York County

Of York County's 188,608 homes, 64% are detached houses, against 57% across Pennsylvania; 8% are in buildings of five or more homes. Much of York County is recent building: 20% of its homes have gone up since 2000 and the middle year built is 1976, against 1965 for Pennsylvania. Owners live in 76% of the occupied homes (Pennsylvania: 69%), so for most households a test and a fix are their own to order.

Homes in York County, Pennsylvania, 2019 to 2023
HomesYork CountyPennsylvania
Housing units188,6085,779,663
Detached houses64%57%
In buildings of 5 or more8%13%
Mobile homes4%4%
Built before 196033%45%
Built since 200020%14%
Middle year built19761965
Owner-occupied76%69%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.