Dubuque County, IA radon potential

Dubuque County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally that's the 94th percentile for radon potential — Dubuque County outranks 94% of every county EPA has rated.

Dubuque County by the numbers

Dubuque County, Iowa is home to about 99,242 people across 608.299 square miles. That works out to roughly 163 people per square mile. Within its own EPA zone, Dubuque County is bigger by population than 82% of the counties that share it. Geologically, Dubuque County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Dubuque County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. That doesn't mean every Dubuque County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

If Dubuque 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 Iowa's state radon program

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

The methodology guide shows exactly which EPA and Census sources feed Dubuque County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.