What EPA's radon map says about Hidalgo County

EPA's own radon map rates Hidalgo County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Hidalgo County sits at the 32nd percentile nationally for radon potential — above 32 of every 100 rated counties.

How Hidalgo County compares

About 914,820 people live in Hidalgo County, Texas, spread over 1,571.217 square miles. That works out to roughly 582 people per square mile. Among counties sharing Hidalgo County's EPA zone, it outranks 97% of them by population. Hidalgo 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, Hidalgo 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 Hidalgo County testing above the action level often enough that skipping a test isn't the safe assumption.

Next steps for a home in Hidalgo County

Mitigation cost doesn't depend on Hidalgo 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 Texas's state radon program

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

More on how this number was built

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