Grady County, OK radon potential

Grady County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Grady County in the 23rd percentile nationally for radon potential — higher than 23% of the counties EPA has rated.

Where Grady County sits nationally

Grady County, Oklahoma is home to about 58,353 people across 1,100.54 square miles. Averaged across its land area, Grady County runs about 53 people per square mile. Within its own EPA zone, Grady County is bigger by population than 70% of the counties that share it. Geologically, Grady County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Grady County's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Grady County testing above the action level often enough that skipping a test isn't the safe assumption.

If Grady County tests above the action level

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Oklahoma's state radon program

For Grady County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Grady 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 Grady County's figures come from

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