Latah County, ID radon potential

EPA places Latah County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 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 Latah County lands in the 88th percentile for radon potential.

How Latah County compares

Latah County, Idaho is home to about 42,180 people across 1,075.867 square miles. Population density there runs about 39 people per square mile. Within its own EPA zone, Latah County is bigger by population than 66% of the counties that share it. Geologically, Latah County is grouped into EPA Region 10 alongside 141 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Latah County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. That doesn't mean every Latah 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.

Testing and mitigation in Latah County

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 Idaho's state radon program

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

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