Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Dauphin County, Pennsylvania
EPA puts Dauphin County in Zone 1, its highest radon zone, and 36.9% of its 2,986 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
36.9%
6.6 pts above PA
- Dauphin
- 36.9%
- PA
- 30.3%
2,986 tests, 2020
Median result
2.0pCi/L
Below action level
- Dauphin
- 2.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2020
Tests reported
2,986
11th of 63 by tests
- Dauphin
- 2,986
- Montgomery
- 10,508
Reported to CDC before any fix, 2020
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in PA
38 of 63
Middle half
- Dauphin
- 36.9%
- Perry
- 57.7%
By share, of 63 with 30+ tests
Read a result for Dauphin County
Starts at Dauphin County's median, 2.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.0 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. Dauphin County's median reported result, 2020.
The data
Dauphin County, At a glance
Dauphin County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Dauphin County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Dauphin County, 2020
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 43.9% |
| 2015 | 45.0% |
| 2016 | 38.0% |
| 2017 | 41.0% |
| 2018 | 32.2% |
| 2019 | 35.1% |
| 2020 | 36.9% |
2020: 36.9%. Across these years the share ran from 32.2% to 45.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 2,986 tests reported to CDC for Dauphin 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).
Dauphin County, Compared
Dauphin County radon figures, compared
Calculated by Radon411In Dauphin County, about 4 in 10 reported tests in 2020 (1,103 of 2,986) were at or above EPA's action level. Against the national pool of 25.5%, the gap is 11.4 points higher. Across 67 Pennsylvania counties pooled together, 30.3% of tests reached that level, so Dauphin County runs 6.6 points above its state.
Of 8 neighbours with a figure, all 8 reported a larger share at or above 4 pCi/L; the spread is 43.3% (Lancaster County) to 57.7% (Perry County). By share, Dauphin County is 38th of 63 Pennsylvania counties with 30 or more tests for the same period.
Year by year, 2014 opened at 43.9% and 2020 closed at 36.9% (down 7.0 points), with 2015 the high at 45.0%. Half the tests came in under 2.0 pCi/L and half over it; the single highest reached 367.0 pCi/L. Below the action level, 1,471 tests (49.3%) came in under 2 pCi/L, against 44.3% statewide, and 412 tests (13.8%) fell between 2 and 4, against 25.4% 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 100% of the county's land high radon potential.
The busiest year on file was 2015, with 4,091 tests reported; the quietest, 2014, had 2,983.
Dauphin CountyPennsylvania, pooled
| Year | Tests | Dauphin County, at or above 4 pCi/L | Pennsylvania, pooled |
|---|---|---|---|
| 2014 | 2,983 | 43.9% | 36.1% |
| 2015 | 4,091 | 45.0% | 37.8% |
| 2016 | 3,708 | 38.0% | 34.4% |
| 2017 | 3,663 | 41.0% | 35.1% |
| 2018 | 3,947 | 32.2% | 30.5% |
| 2019 | 3,572 | 35.1% | 31.4% |
| 2020 | 2,986 | 36.9% | 30.3% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Dauphin County, State data
Pennsylvania's own radon test data
MeasuredWhat Pennsylvania's own agencies publish about radon tests in Dauphin 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 Dauphin County
Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 31 ZIP codes that lie wholly or partly in Dauphin County, each with the state's own figures for it. Period: Period not stated by DEP.
| ZIP code | What the state reports |
|---|---|
| 17005 | Basement: figures not shown; First floor: figures not shown |
| 17017 | Basement: average 19.0 pCi/L, 141 tests; First floor: average 8.9 pCi/L, 34 tests |
| 17018 | Basement: average 10.1 pCi/L, 692 tests; First floor: average 5.4 pCi/L, 124 tests |
| 17020 | Basement: average 18.0 pCi/L, 999 tests; First floor: average 11.4 pCi/L, 158 tests |
| 17022 | Basement: average 7.5 pCi/L, 4,903 tests; First floor: average 4.6 pCi/L, 404 tests |
| 17023 | Basement: average 11.2 pCi/L, 378 tests; First floor: average 7.7 pCi/L, 52 tests |
| 17028 | Basement: average 11.3 pCi/L, 428 tests; First floor: average 5.1 pCi/L, 67 tests |
| 17030 | Basement: average 10.4 pCi/L, 74 tests; First floor: figures not shown |
| 17032 | Basement: average 27.8 pCi/L, 1,378 tests; First floor: average 14.1 pCi/L, 185 tests |
| 17033 | Basement: average 7.3 pCi/L, 5,229 tests; First floor: average 2.9 pCi/L, 2,227 tests |
| 17034 | Basement: average 4.0 pCi/L, 242 tests; First floor: average 1.4 pCi/L, 36 tests |
| 17036 | Basement: average 12.7 pCi/L, 7,946 tests; First floor: average 7.3 pCi/L, 1,169 tests |
| 17048 | Basement: average 13.3 pCi/L, 211 tests; First floor: average 4.1 pCi/L, 43 tests |
| 17057 | Basement: average 6.9 pCi/L, 2,456 tests; First floor: average 3.4 pCi/L, 415 tests |
| 17061 | Basement: average 12.7 pCi/L, 740 tests; First floor: average 6.1 pCi/L, 142 tests |
| 17078 | Basement: average 10.8 pCi/L, 5,709 tests; First floor: average 6.6 pCi/L, 668 tests |
| 17080 | Basement: figures not shown; First floor: figures not shown |
| 17097 | Basement: figures not shown; First floor: figures not shown |
| 17098 | Basement: average 9.5 pCi/L, 113 tests; First floor: figures not shown |
| 17101 | Basement: average 6.1 pCi/L, 229 tests; First floor: average 1.1 pCi/L, 77 tests |
| 17102 | Basement: average 6.0 pCi/L, 817 tests; First floor: average 1.1 pCi/L, 335 tests |
| 17103 | Basement: average 7.0 pCi/L, 548 tests; First floor: average 2.6 pCi/L, 140 tests |
| 17104 | Basement: average 9.5 pCi/L, 1,048 tests; First floor: average 4.5 pCi/L, 331 tests |
| 17109 | Basement: average 10.5 pCi/L, 4,216 tests; First floor: average 4.7 pCi/L, 882 tests |
| 17110 | Basement: average 6.5 pCi/L, 5,049 tests; First floor: average 3.1 pCi/L, 1,249 tests |
| 17111 | Basement: average 15.4 pCi/L, 7,845 tests; First floor: average 8.8 pCi/L, 1,425 tests |
| 17112 | Basement: average 9.0 pCi/L, 9,646 tests; First floor: average 5.2 pCi/L, 1,425 tests |
| 17113 | Basement: average 12.6 pCi/L, 910 tests; First floor: average 11.9 pCi/L, 177 tests |
| 17120 | Basement: figures not shown |
| 17978 | Basement: figures not shown; First floor: figures not shown |
| 17980 | Basement: average 9.4 pCi/L, 164 tests; 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.
Dauphin County, Geology
The ground under Dauphin County
PredictedUSGS's geologic map puts all of Dauphin County's mapped land in one class: high radon potential. The map puts 60.9% of Dauphin County in the area it calls Appalachian Mountain Section and 27.1% in Great Valley Section, with one smaller area beside them. USGS gives the first a radon index of 12 and the second 15, both in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Appalachian Mountain Section | Paleozoic sandstone, shale, and limestone. | High | 12 | 60.9% |
| Great Valley Section | Sandstone, shale and siltstone. | High | 15 | 27.1% |
| Newark Basin | Gray shale and fluvial sandstone. | High | 12 | 12.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Dauphin County beside the ground around it
Dauphin County has more high-potential ground than Pennsylvania as a whole: 100% of its land against 70.4%. Of the 8 counties that border it, none has as large a share of high-potential ground; Juniata County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Dauphin County, Local resources
Radon testing and mitigation in Dauphin County
Listed radon businesses with an address in Dauphin 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.
Listed radon professionals by town: Harrisburg
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
Dauphin County, Questions
Questions about radon in Dauphin County
Are radon levels high in Dauphin County?
In 2020, 36.9% of the radon tests reported to CDC for Dauphin County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.0 pCi/L. Of 63 Pennsylvania counties with 30 or more tests for the same period, 37 reported a higher share; pooled, the state comes to 30.3%.
Which counties border Dauphin County?
Dauphin County borders 8 counties: Lebanon County, Perry County, York County, Cumberland County, Northumberland County, Juniata County, Lancaster County and Schuylkill County.
Products
Dauphin County, Products
Testing a home in Dauphin County
In Dauphin County, 36.9% of 2,986 tests reported to CDC in 2020 reached 4 pCi/L, against 30.3% pooled across Pennsylvania. In Zone 1 the year-round level in Dauphin 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
MonitorForensics Detectors
FD-65-RADON rechargeable radon detector with a color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Dauphin County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Dauphin County
Explore
Dauphin County, Bordering counties
Counties bordering Dauphin County
Calculated by Radon411- Radon levels in Perry CountyEPA zone 1
57.7%at or above 4 pCi/L
Median 4.9 pCi/L · 189 tests · 20.8 points above Dauphin County
- Radon levels in Lebanon CountyEPA zone 1
54.2%at or above 4 pCi/L
Median 4.8 pCi/L · 1,102 tests · 17.3 points above Dauphin County
- Radon levels in Schuylkill CountyEPA zone 1
53.5%at or above 4 pCi/L
Median 4.5 pCi/L · 797 tests · 16.6 points above Dauphin County
- Radon levels in Juniata CountyEPA zone 1
52.9%at or above 4 pCi/L
Median 4.4 pCi/L · 87 tests · 16.0 points above Dauphin County
- Radon levels in Northumberland CountyEPA zone 1
49.8%at or above 4 pCi/L
Median 3.9 pCi/L · 275 tests · 12.9 points above Dauphin County
- Radon levels in York CountyEPA zone 1
46.8%at or above 4 pCi/L
Median 3.6 pCi/L · 3,679 tests · 9.9 points above Dauphin County
- Radon levels in Cumberland CountyEPA zone 1
43.6%at or above 4 pCi/L
Median 3.1 pCi/L · 2,950 tests · 6.7 points above Dauphin County
- Radon levels in Lancaster CountyEPA zone 1
43.3%at or above 4 pCi/L
Median 3.0 pCi/L · 4,398 tests · 6.4 points above Dauphin County
Dauphin County, Cities and towns
Cities and towns in Dauphin County
The Census Bureau estimates 293,351 residents in Dauphin County for July 1, 2025, 6,657 more than in 2020 (+2.3%). That works out to 559 people per square mile of land. No town dominates: Harrisburg, the largest, has 50,522 residents, 17.2% of the total. Together its 17 incorporated places hold 30.6% of those residents; the other 69.4% live outside any of them. CDC's 2,986 reported tests for 2020 work out to 10.2 per 1,000 residents (2025 estimate), close to Pennsylvania's 7.2.
From Harrisburg to Pillow, CDC publishes no figure by town: each reads Dauphin County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Harrisburg | 50,522 | +0.9% | 17.2% |
| Middletown | 9,776 | +2.4% | 3.3% |
| Steelton | 6,328 | +1.1% | 2.2% |
| Hummelstown | 4,492 | −0.2% | 1.5% |
| Penbrook | 3,243 | −0.6% | 1.1% |
| Highspire | 2,725 | −0.4% | 0.9% |
| Millersburg | 2,540 | −0.2% | 0.9% |
| Lykens | 1,856 | −0.2% | 0.6% |
| Paxtang | 1,632 | −0.7% | 0.6% |
| Elizabethville | 1,347 | −0.1% | 0.5% |
| Williamstown | 1,298 | −0.5% | 0.4% |
| Royalton | 1,133 | −0.4% | 0.4% |
Places in Dauphin County with a city page: 1 of 1
- Halifax
- Dauphin
- Gratz
- Berrysburg
- Pillow
17 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).
Dauphin County, Homes
Homes in Dauphin County
Fewer than six in ten of Dauphin County's 127,259 homes are detached houses (50%, against 57% across Pennsylvania); the rest are attached, in shared buildings or mobile. Half of its homes were built before 1970, close to Pennsylvania's 1965: 39% date from before 1960 and 16% from 2000 or later. 63% 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 | Dauphin County | Pennsylvania |
|---|---|---|
| Housing units | 127,259 | 5,779,663 |
| Detached houses | 50% | 57% |
| In buildings of 5 or more | 17% | 13% |
| Mobile homes | 3% | 4% |
| Built before 1960 | 39% | 45% |
| Built since 2000 | 16% | 14% |
| Middle year built | 1970 | 1965 |
| Owner-occupied | 63% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.