38%tests ≥ 4 pCi/L
891tests on record
3.0median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Flathead County

ResultShareEPA guidance
Below 2 pCi/L33%Below EPA's levels
2 to 4 pCi/L29%Consider fixing
4 pCi/L or more38%EPA recommends fixing

What the data shows

Where Flathead County sits among Montana's 51 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017
0%20%40%60%80%100%

How Flathead County compares

Flathead County ranks 7 of 10 among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
Lewis and Clark County62%Powell County59%Lincoln County51%Sanders County50%Missoula County45%Lake County40%Flathead County38%Teton County29%Glacier County14%Pondera County0%Montana 46%
Data table
AreaTests ≥ 4 pCi/LTests
Lewis and Clark County62%468
Powell County59%29
Lincoln County51%74
Sanders County50%38
Missoula County45%2,613
Lake County40%149
Flathead County38%891
Teton County29%7
Glacier County14%7
Pondera County0%5
Montana (51 counties)46%9,893

Same source as Flathead County.

What it means for your home

About 1 in 3 results in Flathead County were at or above 4 pCi/L, where the EPA recommends a fix. Only a test shows your own home's level.

Levels in pCi/L from the EPA. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.

Test your home

Start with a short-term test (2–90 days) and confirm a result of 4 pCi/L or more with a second test. EPA guide

Sponsored: we earn a commission on purchases through these links. We haven't tested Airthings monitors yet.

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Fixing high radon

No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →

About this data

Source: Radon test results from laboratories (CDC Environmental Public Health Tracking Network). Period: 2008–2017. Tests: 891. Read the methodology →

These are voluntary and real-estate tests, not a random sample of homes, so they describe tested homes rather than every home.

About this page

Published by Ray Roman, editor of Radon by County. Figures are loaded from the cited source and spot-checked against it. Editorial policy · About us