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

EPA places Hemphill County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Rank it against the rest of the country and Hemphill County lands in the 35th percentile for radon potential.

How Hemphill County compares

Hemphill County, Texas is home to about 3,134 people across 906.286 square miles. Averaged across its land area, Hemphill County runs about 3 people per square mile. By population, Hemphill County is the 982nd largest of every county sharing its EPA zone — the 5th percentile by population within that zone. EPA's geology-based Region 6 groups Hemphill County with 502 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Hemphill County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. Hemphill County's Zone 2 rating sits in the middle nationally; EPA's guidance is unchanged by that — test every home regardless of its zone.

Next steps for a home in Hemphill County

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

Hemphill County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.