Kidder County, ND: EPA's radon zone, explained

Kidder 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 68th percentile for radon potential — Kidder County outranks 68% of every county EPA has rated.

Where Kidder County sits nationally

Kidder County, North Dakota is home to about 2,371 people across 1,351.062 square miles. That works out to roughly 2 people per square mile. By population, Kidder County is the 1012th largest of every county sharing its EPA zone — the 5th percentile by population within that zone. EPA's geology-based Region 8 groups Kidder County with 290 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Kidder County

Kidder 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 Kidder 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.

Next steps for a home in Kidder County

For a Kidder 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 North Dakota's state radon program

For Kidder County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Kidder 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 Kidder 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 Kidder County carries, the zone explainer covers what it does and doesn't tell you about any one house.