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Radon Levels in St. Louis County, Minnesota

EPA puts St. Louis County in Zone 2, its middle radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

Predicted
Zone 2Moderate predicted potential
Measured
20.2%of 496 tests reported to CDC (2023) were at or above 4 pCi/L
Your home
Test to knowNo area figure here is a reading of your home.
How to test this homeFind a certified tester

The data

St. Louis County, At a glance

St. Louis County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.

What EPA predicts hereScreening level, geology

EPA predicts an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³) across the county as a whole.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for St. Louis County, 2023

Tests reported
496
At or above 4 pCi/L
20.2%
Median result
1.7 pCi/L
Reported results by concentration band, St. Louis County, 2023
Under 2 pCi/L: 55%2 to 4 pCi/L: 25%4 pCi/L and above: 20%

Of 496 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, St. Louis County, 2023: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L27455.2%
2 to 4 pCi/L12224.6%
4 pCi/L and above10020.2%

CDC publishes this figure only for counties here, so there is no state or national number to compare St. Louis County, Minnesota with.

What these figures count

Distribution of radon tests reported to CDC, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.

The figures at the top are for 2023: a percentage there is a share of radon tests reported to CDC for St. Louis County in 2023, and a percentage in a view below is a share of the tests reported for the year or period it names. It is not a share of homes in St. Louis County, and it is not a random sample: it counts only the tests people chose to run and that were reported.

CDC works out the shares and the median over pre-mitigation tests, counting a test not marked as before or after mitigation as one of them (496 for 2023). The median is the middle result of those tests, not of buildings. CDC also reports the number of buildings tested (309), a different count, so the two totals are not interchangeable.

St. Louis County's own published CDC figures beside those of the counties that border it, for the same period.

Each figure is that county’s own published CDC figure for 2023, counting radon tests reported to CDC, not homes. St. Louis County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. Every Minnesota county’s own figure is in the Minnesota county table.

Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

St. Louis County, State data

Minnesota's own radon test data

Measured

What Minnesota's own agencies publish about radon tests in St. Louis County, with their period. These are not CDC's figures and are never added to them.

MeasuredState figures, not CDC's

What the Minnesota Department of Health reports for St. Louis County

Radon Testing (MN Public Health Data Access Portal): home radon tests reported voluntarily by private laboratories and licensed radon measurement professionals, counted by property. Period: 2016-2025.

Share with one or more tests at or above 4 pCi/L

26.6%

1,602 properties tested with one or more tests at or above 4 pCi/L

Median result

2.2 pCi/L

Average result

3.3 pCi/L

Tests behind these figures

602 properties tested a year on average

  • MDH says these data do not include all of the radon tests conducted in Minnesota.
  • Post-mitigation tests are excluded from the averages and the median; the percentages use each property's highest test.
  • Each home is unique and can have very different results than a neighbor's home; the only way to know is to test.
  • These figures describe tests reported to the Minnesota Department of Health in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.

Measured: Minnesota Department of Health data, 2016-2025.

Radon Action Brief

National Radon Action MonthPre-sale

St. Louis County's radon brief, in one dated file.

  • Your area's radon record, explained.
  • Your plan to test this week.
  • Fix costs and pros near you.

Save 64%Sale price: $8.99Price after the sale: $25Ends Jan 31Then $25

Get the St. Louis County BriefSee a free sample

Area data, not a test of the building.

Local help

St. Louis County, Local resources

Radon testing and mitigation in St. Louis County

Who tests and fixes radon in St. Louis County: listed businesses, Minnesota's radon program and test kits.

Listed radon businesses with an address in St. Louis County:

Listed radon professionals by town: Duluth, Hibbing, Proctor

What Minnesota's program says
Phone
651-201-4601
Email
health.indoorair@state.mn.us
Licensing of radon professionals
The Radon Licensing Act requires anyone who performs a radon test or radon mitigation, in a building they do not own or lease, must be licensed by MDH.
Disclosure when a home is sold or rented
The Minnesota Radon Awareness Act requires specific disclosure and education be provided to potential home buyers during residential real estate transactions in Minnesota.

What it means

St. Louis County, Questions

Questions about radon in St. Louis County

Common questions

8 questions, answered from the figures above

Are radon levels high in St. Louis County?

In 2023, 20.2% of the radon tests reported to CDC for St. Louis County, Minnesota were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.7 pCi/L. That is a share of reported tests, not of homes. EPA places St. Louis County in Zone 2, moderate predicted potential, a predicted average indoor screening level 2 to 4 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.

Radon levels: what a result meansWhat is radon?Radon levels in Minnesota

How do I get a radon test in St. Louis County?

EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No radon testing business listed on Radon411 has an address in St. Louis County or names it as a service area yet. The Minnesota radon program is the place to ask about certified testers and any test kit offer it runs.

Radon testing: how to test a homeRadon test kits comparedFree and low-cost kits by stateRadon Action Month checklistMinnesota radon program

Who does radon mitigation in St. Louis County?

No listed mitigator names St. Louis County as a service area yet; the Minnesota directory lists 253 companies. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether Minnesota requires one.

Radon mitigation: how it worksRadon mitigation costRadon mitigation systemsMitigators in Minnesota

What EPA radon zone is St. Louis County in?

EPA places St. Louis County, Minnesota in Zone 2, which EPA describes as moderate predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.

Should I test my home in St. Louis County?

Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.

When is the best time of year to test?

EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.

What does it cost to test?

EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.

Which counties border St. Louis County?

St. Louis County borders 6 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.

If you own, buy, sell or rent

What these figures mean for each reader, with the guide that covers it

The reported-test figures on this page describe St. Louis County, Minnesota in 2023. They describe tests other people carried out in other buildings, and none of them measures yours.

St. Louis County in figures

The figures above, said in words

What the published data says about St. Louis County, in words. A zone and a share of tests describe an area, never the level in any one home.

    • Predicted

      Predicted

      EPA places St. Louis County in Zone 2, moderate predicted potential, as it does 18 other counties of Minnesota's 87.

      Of the 6 bordering counties, EPA places Aitkin County, Carlton County, Douglas County, WI, Itasca County, Koochiching County and Lake County in Zone 2.

  • Reported tests

    Measured

    CDC has annual figures for St. Louis County for 10 years, 2014 to 2023. In 2023, 20.2% of 496 reported tests were at or above 4 pCi/L.

    Across those years the share ranged from 20.2% (2023) to 31.1% (2019). Few tests in a year can move it a long way.

  • Local record

    Minnesota's radon program is the MDH Indoor Air Unit, run by MN Dept. of Health; its contacts are under Local resources.

    The county's largest incorporated places are Duluth, Hibbing and Hermantown; the figures here cover them as part of the county.

Products

St. Louis County, Products

Testing and mitigation products

Whatever the figures for St. Louis County show, only a test tells you about one home.

Test kits and monitors42

See all products

As an Amazon Associate, Radon411 earns from qualifying purchases.

Best radon monitors for St. Louis County homes, compared

Testing

5

Mitigation

3

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St. Louis County, Bordering counties

Counties bordering St. Louis County

Calculated by Radon411
Why bordering counties matter

6 counties share a boundary with St. Louis County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.

St. Louis County, Cities and towns

Cities and towns in St. Louis County

The radon figures on this page are for St. Louis County as a whole. They do not differ by city or town.

  • Hibbing
  • Hermantown
  • Virginia
  • Chisholm
  • Rice Lake
  • Eveleth
  • Ely
  • Proctor
  • Mountain Iron
  • Hoyt Lakes
  • Gilbert
  • Aurora
  • Babbitt
  • Biwabik
  • Buhl
  • Cook
  • Floodwood
  • Tower
  • Orr
  • Winton
  • Kinney
  • Meadowlands
  • Brookston
  • Iron Junction
The other 2 places in St. Louis County
  • McKinley
  • Leonidas

27 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.

St. Louis County, Next steps

What to do next

  1. LearnKnow what radon isWhat radon is, how it gets indoors, and why a county zone is not a reading for your home.Learn about radon
  2. TestTest the building you live inShort-term or long-term, where the device goes, and closed-house conditions.How to test
  3. FixBring a high level downHow a mitigation system works, and the retest that confirms it.How mitigation works
  4. Find a proHire a certified professionalMeasurement and mitigation professionals by state, with their certifications.Find a professional

Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.