76%tests ≥ 4 pCi/L
70tests on record
6.5median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Sheridan County

ResultShareEPA guidance
Below 2 pCi/L4%Below EPA's levels
2 to 4 pCi/L20%Consider fixing
4 pCi/L or more76%EPA recommends fixing

What the data shows

Where Sheridan 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 Sheridan County compares

Sheridan County ranks 2 of 5 among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
Roosevelt County94%Sheridan County76%Divide County, North Dako…50%Williams County, North Da…34%Daniels County0%Montana 46%
Data table
AreaTests ≥ 4 pCi/LTests
Roosevelt County94%16
Sheridan County76%70
Divide County, North Dakota50%14
Williams County, North Dakota34%204
Daniels County0%3
Montana (51 counties)46%9,893

Same source as Sheridan County.

What it means for your home

More than half of all results in Sheridan 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: 70. 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