Mohave County, AZ: EPA's radon zone, explained
EPA places Mohave 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 Mohave County lands in the 63rd percentile for radon potential.
Mohave County by the numbers
Mohave County, Arizona is home to about 226,479 people across 13,332.121 square miles. Averaged across its land area, Mohave County runs about 17 people per square mile. By population, Mohave County is the 107th largest of every county sharing its EPA zone — the 90th percentile by population within that zone. EPA's geology-based Region 9 groups Mohave County with 94 other counties nationally sharing its underlying rock and soil profile.
Zone vs. an actual test
Call it a middle case: above the 1.3 pCi/L most US homes average, below the 4 pCi/L line EPA uses to recommend mitigation — that's Mohave County's Zone 2 prediction. A county-wide moderate average, like Mohave County's, can still hide a specific house well above or below it — testing is what actually answers the question.
If Mohave County tests above the action level
For a Mohave 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 Arizona's state radon program
For Mohave County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Mohave County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.
Where Mohave 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. Whatever zone Mohave County carries, the zone explainer covers what it does and doesn't tell you about any one house.