Noble County, OH: EPA's radon zone, explained

EPA's own radon map rates Noble County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Rank it against the rest of the country and Noble County lands in the 43rd percentile for radon potential.

How Noble County compares

Noble County, Ohio is home to about 14,269 people across 397.969 square miles. Population density there runs about 36 people per square mile. By population, Noble County is the 729th largest of every county sharing its EPA zone — the 29th percentile by population within that zone. Geologically, Noble County is grouped into EPA Region 5 alongside 523 other counties that share its rock and soil setting.

What this actually means for a house in Noble County

Noble County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). A county-wide moderate average, like Noble County's, can still hide a specific house well above or below it — testing is what actually answers the question.

If Noble County tests above the action level

For a Noble County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Ohio's state radon program

For Noble County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Noble County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

Where Noble County's figures come from

Noble County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Noble County carries, the zone explainer covers what it does and doesn't tell you about any one house.