52%tests ≥ 4 pCi/L
28,462tests on record
4.3median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Franklin County

ResultShareEPA guidance
Below 2 pCi/L29%Below EPA's levels
2 to 4 pCi/L19%Consider fixing
4 pCi/L or more52%EPA recommends fixing

What the data shows

Where Franklin County sits among Pennsylvania's 67 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Pennsylvania county radon test results, 1986–2026
0%20%40%60%

How Franklin County compares

Franklin County ranks 4 of 7 among its neighboursShare of tests at or above 4 pCi/L · Pennsylvania county radon test results, 1986–2026 · whisker: 95% range
Fulton County66%Juniata County59%Perry County58%Franklin County52%Cumberland County50%Huntingdon County47%Adams County38%Pennsylvania 34%
Data table
AreaTests ≥ 4 pCi/LTests
Fulton County66%881
Juniata County59%2,068
Perry County58%7,114
Franklin County52%28,462
Cumberland County50%103,521
Huntingdon County47%4,906
Adams County38%22,476
Pennsylvania (67 counties)34%3,356,893

Same source as Franklin County. Other bordering counties: Frederick County, Maryland, Washington County, Maryland.

What it means for your home

More than half of all results in Franklin County were at or above 4 pCi/L, where the EPA recommends a fix. Only a test shows your own home's level.

Levels in pCi/L from the EPA. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.

Test your home

Start with a short-term test (2–90 days) and confirm a result of 4 pCi/L or more with a second test. EPA guide

Sponsored: we earn a commission on purchases through these links. We haven't tested Airthings monitors yet.

Prefer a digital monitor? See Airthings radon monitors, or enter code radonbycounty-10OFF at their discount store for 10% off.

Fixing high radon

No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →

Pennsylvania licenses radon mitigators. Source

Buying or selling here

Pennsylvania's required Seller's Property Disclosure Statement asks whether the seller knows of hazardous substances on the property, including radon (49 Pa. Code § 35.335a). Source

Checked against the official text on 2026-11-03. Not legal advice.

About this data

Source: Pennsylvania county radon test results (Pennsylvania Department of Environmental Protection). Period: 1986–2026. Tests: 28,462. Read the methodology →

These are voluntary and real-estate tests, not a random sample of homes, so they describe tested homes rather than every home.

About this page

Published by Ray Roman, editor of Radon by County. Figures are loaded from the cited source and spot-checked against it. Editorial policy · About us