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Radon in Warren County, Pennsylvania

Warren County, Pennsylvania, is in EPA radon Zone 2: predicted average indoor radon screening level from 2 to 4 pCi/L (moderate potential). Radon laboratories reported 364 building tests here for 2008 to 2017: median 4.4 pCi/L, with 54.6% at or above EPA's 4 pCi/L action level (Pennsylvania 41.1%, US 36.5%). Pennsylvania state records have 4,968 test results on file for the county, median 3.2 pCi/L, 42.8% at or above 4 pCi/L.

Zone 2
EPA radon zone (1993 county map)
4.4
median lab test, pCi/L (2008-2017)
54.6%
of lab tests at or above 4 pCi/L
364
buildings tested by labs, 2008-2017

Radon test results in Warren County

Radon test results on file for Warren County, PA, with state and national comparison
Test resultsPeriodTestsTypical result4 pCi/L or more
Radon testing laboratories2008-2017364median 4.4 pCi/L54.6%
Pennsylvania state records, every reported test1986 to 2026-074,968median 3.2 pCi/L42.8%
Pennsylvania, all counties (labs)2008-2017173,284n/a41.1%
United States (labs)2008-20171,408,802n/a36.5%

Test results describe buildings whose owners chose to test and whose results reached the lab or agency, not a random sample; small counts swing widely. State and US shares are computed from county counts and percents. The laboratory data comes from national radon testing laboratories and supplements EPA's zone map.

Radon levels by ZIP code in Warren County

Pennsylvania state results for the ZIP codes with 10 or more tests reported in Warren County, 1986 to 2026-07.

ZIP codeTestsMedian4 pCi/L or more
16313842.7 pCi/L42.9%
16329642.6 pCi/L31.2%
16340954.1 pCi/L51.6%
163459094.1 pCi/L51.8%
16347781.6 pCi/L16.7%
163501092.2 pCi/L30.3%
16351612.8 pCi/L39.3%
163653,0653.0 pCi/L40.3%
163712573.6 pCi/L46.3%
16402241.6 pCi/L37.5%
16405402.8 pCi/L35%
164071276.1 pCi/L60.6%
16420162.2 pCi/L31.2%
16436158.9 pCi/L80%

Radon in nearby counties

CountyEPA zoneLab tests4 pCi/L or more
Forest County, PAZone 23744.7%
Chautauqua County, NYZone 185538%
McKean County, PAZone 214426.4%
Venango County, PAZone 166948.4%
Crawford County, PAZone 287833.4%
Cattaraugus County, NYZone 152540.6%

The six counties with the nearest centers.

What to do about radon in Warren County

Test the building. EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, and says there is no known safe level of exposure. The state environmental protection agency runs the state's radon program.

Buying here? The Environmental Records Report lists this county's radon zone and test results with the flood zone, mapped faults, power lines and federal contamination records near the address.

Check one Warren County address

Environmental Records Report, $29. PDF and JSON, usually ready in about a minute.

Radon in Warren County: questions

What is the radon level in Warren County?

The median of the 364 laboratory tests reported for Warren County (2008 to 2017) was 4.4 pCi/L, and 54.6% of them were at or above 4 pCi/L. Pennsylvania's 4,968 state results have a median of 3.2 pCi/L. These are results of tested buildings; a single home can be far above or below them.

Is Warren County in radon Zone 1?

No. EPA's 1993 map puts Warren County in Zone 2 (predicted average indoor radon screening level from 2 to 4 pCi/L (moderate potential)). EPA says homes in every zone can have high radon and should be tested.

How does radon in Warren County compare with Pennsylvania?

54.6% of laboratory tests in Warren County were at or above 4 pCi/L for 2008 to 2017, against 41.1% across Pennsylvania (173,284 tests) and 36.5% nationally. 49 of Pennsylvania's 67 counties are in Zone 1.

Should I test for radon in Warren County?

Yes. EPA recommends testing every home whatever its zone: "This map should not be used to determine if individual homes need to be tested." Fix the home at 4 pCi/L or more and consider a fix between 2 and 4 pCi/L; EPA says there is no known safe level of radon exposure.

More for Warren County

Other free hazard lookups

All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).

Radon in every Pennsylvania county · Radon map of every state

Data compiled 2026-10-20. County FIPS 42123. County-level screening information, not a radon measurement of any building.