What EPA's radon map says about Oklahoma County

Oklahoma County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Oklahoma County sits at the 32nd percentile nationally for radon potential — above 32 of every 100 rated counties.

Where Oklahoma County sits nationally

About 816,490 people live in Oklahoma County, Oklahoma, spread over 708.9 square miles. Averaged across its land area, Oklahoma County runs about 1,152 people per square mile. Among counties sharing Oklahoma County's EPA zone, it outranks 97% of them by population. Oklahoma County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

At Zone 3, Oklahoma County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Oklahoma County testing above the action level often enough that skipping a test isn't the safe assumption.

Next steps for a home in Oklahoma County

Mitigation cost doesn't depend on Oklahoma County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Oklahoma's state radon program

Oklahoma County's test kit answers today; a Airthings radon monitor keeps answering for Oklahoma County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Oklahoma County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.