27%properties ≥ 4 pCi/L
602properties tested annually (avg.)
2.2median pCi/L
Zone 2EPA zone (1993 prediction)

Highest result per tested property in St. Louis County

ResultShareEPA guidance
Below 2 pCi/L44%Below EPA's levels
2 to 4 pCi/L30%Consider fixing
4 pCi/L or more27%EPA recommends fixing

What the data shows

Where St. Louis County sits among Minnesota's 87 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Minnesota county radon testing indicators, 2016–2025
0%20%40%60%80%

How St. Louis County compares

St. Louis County ranks 5 of 6 among its neighboursShare of properties at or above 4 pCi/L · Minnesota county radon testing indicators, 2016–2025
Carlton County42%Aitkin County33%Itasca County31%Koochiching County28%St. Louis County27%Lake County26%
Data table
AreaProperties ≥ 4 pCi/L
Carlton County42%
Aitkin County33%
Itasca County31%
Koochiching County28%
St. Louis County27%
Lake County26%

Same source as St. Louis County. Other bordering counties: Douglas County, Wisconsin.

What it means for your home

About 1 in 4 results in St. Louis 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 →

Minnesota licenses radon mitigators. Source

Buying or selling here

Minnesota's Radon Awareness Act requires sellers to disclose in writing any known radon tests, results and mitigation, and to give buyers the Department of Health publication "Radon in Real Estate Transactions" (Minn. Stat. § 144.496). Source

Checked against the official text on 2026-11-03. Not legal advice.

About this data

Source: Minnesota county radon testing indicators (Minnesota Department of Health). Period: 2016–2025. Published indicators: 1,602 properties at or above 4 pCi/L, 3,394 at or above 2 pCi/L, and 602 properties tested annually on average. 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