Cooke County, TX: EPA's radon zone, explained

EPA's own radon map rates Cooke County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. That puts Cooke County in the 21st percentile nationally for radon potential — higher than 21% of the counties EPA has rated.

Where Cooke County sits nationally

Cooke County, Texas is home to about 44,258 people across 874.826 square miles. That works out to roughly 51 people per square mile. By population, Cooke County is the 377th largest of every county sharing its EPA zone — the 63rd percentile by population within that zone. Geologically, Cooke County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

What this actually means for a house in Cooke County

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Cooke County's Zone 3 prediction is the low end of the scale. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Cooke County testing above the action level often enough that skipping a test isn't the safe assumption.

If Cooke County tests above the action level

For a Cooke 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 Texas's state radon program

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

Where Cooke County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.