Is radon high in Minnesota?

Minnesota's population-weighted predicted basement average is 2.4 pCi/L, about 1.4× the US average of 1.8. 9 of its 87 modeled counties are predicted at or above the EPA action level of 4 pCi/L, 73 are in the 2-4 "consider fixing" range and 5 are below 2. 8.6% of Minnesota ZIP codes are predicted at 4 or higher.

Which Minnesota county has the highest radon?

Rock County has the highest predicted basement average in Minnesota at 4.7 pCi/L (EPA Zone 1). The lowest is Anoka County at 1.8 pCi/L. In measured state test data (2016-2025), Rock County has the largest share of results at or above 4 pCi/L (77.3%). These are area figures; individual homes in any county can test far higher.

How many EPA Zone 1 counties are in Minnesota?

68 of Minnesota's 87 counties (78%) are EPA Zone 1 (highest potential), 19 are Zone 2 and 0 are Zone 3. The EPA zone map dates from 1993; the predicted values on this page come from a 2001-2021 model built on millions of actual tests, so the two can disagree for a given county.

Should I test for radon in Minnesota?

Yes - with some urgency. Minnesota's predicted average is in the moderate range, and 84.7% of its ZIP codes are predicted at 2 pCi/L or higher. A short-term charcoal kit or a continuous digital monitor will tell you your actual level within days.

Radon levels in Minnesota: Moderate

Name: Radon levels by county for Minnesota
Creator: RadonGrade
License: https://creativecommons.org/licenses/by/4.0/

The model predicts a population-weighted basement average of 2.4 pCi/L (model estimate) across Minnesota's 87 counties - about 1.4× the US average of 1.8 pCi/L. Above-ground floors average 1.7 pCi/L.

Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. Measured state test results are shown separately below, labeled with their source and years. How the numbers work.

68 / 87

EPA Zone 1 counties (78%)

19 / 0

Zone 2 / Zone 3 counties

counties predicted ≥ 4 pCi/L

8.6%

of ZIP codes predicted ≥ 4 pCi/L

Test Minnesota - the EPA says "consider fixing" in this range

The predicted basement average here is 2.4 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.

Get a short-term test kit →Or track it with a continuous monitor

Monitor link goes to the Airthings store - use code RADONGRADE-10OFF at checkout for 10% off any Airthings monitor.

Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.

Affiliate links: we may earn a commission from Airthings or Amazon at no extra cost to you.

What the data says about radon in Minnesota

On the EPA's 1993 radon zone map, 68 of Minnesota's 87 counties are EPA Zone 1 (78%), 19 are Zone 2 and 0 are Zone 3. Zone 1 - the highest-potential class, predicted screening average above 4 pCi/L - is the most common designation in Minnesota. That classification has not been revised since 1993; it describes counties, not homes, and elevated readings turn up in Zone 3 counties every year.

Minnesota models out at 2.4 pCi/L predicted basement average (moderate; 1.4× the US population-weighted average of 1.8). Of the 87 counties with predictions, 9 are predicted at or above 4 pCi/L, 73 in the 2-4 band and 5 below 2. The highest predicted county is Rock County at 4.7 pCi/L; the lowest is Anoka County at 1.8 - a 2.9 pCi/L spread that means a statewide average tells you little about any one county.

At ZIP-code resolution, 8.6% of Minnesota ZIPs are predicted at 4 pCi/L or higher in the basement and 84.7% at 2 or higher - above the national shares of 4.2% and 48.7%. With more than half of ZIPs above 2, a test is worth doing before any purchase or renovation here.

Measured data exists for Minnesota: Minnesota Department of Health (MN Public Health Data Access) publishes 2016-2025 results for 87 counties (the published tests). The county with the largest share of elevated results is Rock County (77.3%); the smallest is Anoka County (15.3%). In 87 of the 87 counties with both figures, the measured mean is higher than the model's long-term basement estimate - expected, because state tests are voluntary and skew toward basements and homeowners who suspected a problem. Each county page shows both side by side.

Minnesota counties by predicted radon

Sorted highest to lowest predicted basement average (model estimate). 87 counties. The “Measured ≥ 4” column is the share of Minnesota Department of Health (MN Public Health Data Access) test results at or above 4 pCi/L, 2016-2025.

County	Predicted basement	Upstairs	Grade	EPA zone	Measured ≥ 4	ZIPs
Rock County	4.7 pCi/L	2.6	High	EPA Zone 1	77.3%	9
Murray County	4.4 pCi/L	2.5	High	EPA Zone 1	73.7%	7
Lincoln County	4.3 pCi/L	2.5	High	EPA Zone 1	73.2%	6
Nobles County	4.3 pCi/L	2.3	High	EPA Zone 1	71.8%	10
Jackson County	4.2 pCi/L	2.3	High	EPA Zone 1	71.7%	6
Pipestone County	4.2 pCi/L	2.4	High	EPA Zone 1	68.8%	5
Renville County	4.1 pCi/L	2.4	High	EPA Zone 1	70.1%	10
Cottonwood County	4.1 pCi/L	2.4	High	EPA Zone 1	64.6%	6
Lac qui Parle County	4.0 pCi/L	2.4	High	EPA Zone 1	67.9%	5
Lyon County	4.0 pCi/L	2.1	Moderate	EPA Zone 1	63.7%	9
Redwood County	3.9 pCi/L	2.3	Moderate	EPA Zone 1	64.7%	14
Yellow Medicine County	3.9 pCi/L	2.4	Moderate	EPA Zone 1	65.5%	7
Brown County	3.9 pCi/L	2.4	Moderate	EPA Zone 1	62.4%	5
Polk County	3.9 pCi/L	2.1	Moderate	EPA Zone 1	69.9%	16
Martin County	3.8 pCi/L	2.3	Moderate	EPA Zone 1	63.9%	10
Chippewa County	3.8 pCi/L	2.3	Moderate	EPA Zone 1	68.6%	5
Fillmore County	3.7 pCi/L	2.7	Moderate	EPA Zone 1	59.6%	11
Watonwan County	3.7 pCi/L	2.3	Moderate	EPA Zone 1	58.4%	5
Faribault County	3.6 pCi/L	2.3	Moderate	EPA Zone 1	63.4%	9
Traverse County	3.6 pCi/L	2.3	Moderate	EPA Zone 1	59.6%	3
Douglas County	3.6 pCi/L	2.2	Moderate	EPA Zone 1	55.8%	8
Big Stone County	3.6 pCi/L	2.2	Moderate	EPA Zone 1	59.5%	6
Freeborn County	3.6 pCi/L	2.1	Moderate	EPA Zone 1	65.8%	10
Stevens County	3.6 pCi/L	2.3	Moderate	EPA Zone 1	60.7%	5
Sibley County	3.5 pCi/L	2.3	Moderate	EPA Zone 1	62.8%	6
Waseca County	3.5 pCi/L	2.4	Moderate	EPA Zone 1	60.1%	4
Kandiyohi County	3.5 pCi/L	2.4	Moderate	EPA Zone 1	63.9%	11
Wabasha County	3.5 pCi/L	2.4	Moderate	EPA Zone 1	56.8%	8
Clay County	3.5 pCi/L	2.1	Moderate	EPA Zone 1	59.4%	10
Grant County	3.4 pCi/L	2.1	Moderate	EPA Zone 1	66.7%	7
Steele County	3.4 pCi/L	2.1	Moderate	EPA Zone 1	58.9%	4
Houston County	3.3 pCi/L	2.4	Moderate	EPA Zone 1	52%	7
Dodge County	3.3 pCi/L	2.3	Moderate	EPA Zone 1	60.8%	6
Norman County	3.3 pCi/L	2.0	Moderate	EPA Zone 1	57.9%	8
Marshall County	3.3 pCi/L	1.9	Moderate	EPA Zone 1	46.3%	9
McLeod County	3.2 pCi/L	1.9	Moderate	EPA Zone 1	58.3%	8
Goodhue County	3.2 pCi/L	2.2	Moderate	EPA Zone 1	51.5%	10
Winona County	3.2 pCi/L	2.0	Moderate	EPA Zone 1	41.3%	8
Nicollet County	3.2 pCi/L	2.2	Moderate	EPA Zone 1	55.6%	5
Blue Earth County	3.2 pCi/L	2.3	Moderate	EPA Zone 1	57.2%	12
Red Lake County	3.2 pCi/L	1.9	Moderate	EPA Zone 1	56.8%	4
Swift County	3.2 pCi/L	2.0	Moderate	EPA Zone 1	52.9%	6
Mahnomen County	3.2 pCi/L	1.8	Moderate	EPA Zone 1	45.9%	5
Meeker County	3.2 pCi/L	2.1	Moderate	EPA Zone 1	51.3%	7
Rice County	3.2 pCi/L	2.0	Moderate	EPA Zone 1	55.5%	8
Kittson County	3.1 pCi/L	1.9	Moderate	EPA Zone 1	27.9%	8
Otter Tail County	3.1 pCi/L	1.9	Moderate	EPA Zone 1	59.9%	20
Pope County	3.1 pCi/L	1.9	Moderate	EPA Zone 1	51.5%	8
Le Sueur County	3.1 pCi/L	2.2	Moderate	EPA Zone 1	58.2%	9
Wilkin County	3.1 pCi/L	2.0	Moderate	EPA Zone 1	52.8%	7
Becker County	3.0 pCi/L	1.8	Moderate	EPA Zone 1	54.3%	9
Olmsted County	2.9 pCi/L	1.9	Moderate	EPA Zone 1	41.7%	10
Todd County	2.9 pCi/L	1.9	Moderate	EPA Zone 1	43.3%	11
Wadena County	2.9 pCi/L	1.8	Moderate	EPA Zone 1	30.7%	4
Mower County	2.8 pCi/L	1.9	Moderate	EPA Zone 1	42.8%	14
Pennington County	2.8 pCi/L	1.3	Moderate	EPA Zone 1	56.3%	3
Clearwater County	2.7 pCi/L	1.6	Moderate	EPA Zone 2	43.9%	6
Stearns County	2.6 pCi/L	1.9	Moderate	EPA Zone 1	45.3%	19
Wright County	2.6 pCi/L	2.0	Moderate	EPA Zone 1	42.3%	12
Hubbard County	2.6 pCi/L	1.7	Moderate	EPA Zone 1	39.2%	5
Cass County	2.5 pCi/L	1.4	Moderate	EPA Zone 2	31.6%	13
Morrison County	2.4 pCi/L	1.4	Moderate	EPA Zone 2	36.7%	9
Beltrami County	2.4 pCi/L	1.0	Moderate	EPA Zone 2	39%	12
Sherburne County	2.3 pCi/L	1.8	Moderate	EPA Zone 1	31.9%	6
Roseau County	2.3 pCi/L	1.1	Moderate	EPA Zone 1	29.6%	7
Carlton County	2.3 pCi/L	1.1	Moderate	EPA Zone 2	41.5%	11
Kanabec County	2.3 pCi/L	1.2	Moderate	EPA Zone 1	34.9%	4
Itasca County	2.3 pCi/L	1.1	Moderate	EPA Zone 2	30.7%	18
Chisago County	2.3 pCi/L	1.8	Moderate	EPA Zone 2	28.3%	9
Scott County	2.3 pCi/L	1.7	Moderate	EPA Zone 1	40.8%	7
Benton County	2.3 pCi/L	1.3	Moderate	EPA Zone 2	23.1%	4
Cook County	2.3 pCi/L	1.5	Moderate	EPA Zone 2	40.6%	6
Pine County	2.2 pCi/L	1.4	Moderate	EPA Zone 2	32.9%	11
Hennepin County	2.2 pCi/L	1.6	Moderate	EPA Zone 1	34%	64
Carver County	2.2 pCi/L	1.8	Moderate	EPA Zone 1	34.9%	12
Crow Wing County	2.2 pCi/L	1.0	Moderate	EPA Zone 2	30.7%	12
Dakota County	2.1 pCi/L	1.6	Moderate	EPA Zone 1	33.9%	18
Aitkin County	2.1 pCi/L	1.1	Moderate	EPA Zone 2	32.8%	9
Mille Lacs County	2.1 pCi/L	1.4	Moderate	EPA Zone 2	27.7%	6
Koochiching County	2.0 pCi/L	1.0	Moderate	EPA Zone 2	28.4%	7
Ramsey County	2.0 pCi/L	1.4	Moderate	EPA Zone 1	26.8%	19
Isanti County	2.0 pCi/L	1.4	Moderate	EPA Zone 2	15.7%	4
Lake of the Woods County	2.0 pCi/L	1.2	Low	EPA Zone 2	20%	3
Washington County	1.9 pCi/L	1.5	Low	EPA Zone 1	27.9%	15
Lake County	1.9 pCi/L	1.0	Low	EPA Zone 2	25.6%	5
St. Louis County	1.8 pCi/L	1.0	Low	EPA Zone 2	26.6%	39
Anoka County	1.8 pCi/L	1.4	Low	EPA Zone 2	15.3%	14

Radon levels in Minnesota cities

The 23 most-populous Minnesota places among the 1,000 largest US cities (Census incorporated places and CDPs), by population. City figures are ZIP-land-weighted means of the model's ZIP predictions (model estimate).

City	Population	Predicted basement	Upstairs	Grade	ZIPs ≥ 4
Minneapolis	425,115	2.1 pCi/L	1.4	Moderate	0%
St. Paul	303,820	2.0 pCi/L	1.3	Low	0%
Rochester	122,413	2.9 pCi/L	1.9	Moderate	0%
Duluth	87,680	1.8 pCi/L	1.0	Low	0%
Bloomington	87,398	2.5 pCi/L	1.8	Moderate	0%
Brooklyn Park	82,017	1.9 pCi/L	1.5	Low	0%
Woodbury	79,538	1.6 pCi/L	1.3	Low	0%
Plymouth	77,648	2.0 pCi/L	1.7	Low	0%
Lakeville	76,243	1.9 pCi/L	1.5	Low	0%
Blaine	73,774	1.2 pCi/L	1.1	Low	0%
Maple Grove	71,288	1.9 pCi/L	1.6	Low	0%
St. Cloud	71,013	2.5 pCi/L	1.9	Moderate	0%
Eagan	67,396	1.8 pCi/L	1.4	Low	0%
Burnsville	64,772	2.1 pCi/L	1.6	Moderate	0%
Coon Rapids	63,377	1.9 pCi/L	1.5	Low	0%
Eden Prairie	62,166	2.1 pCi/L	1.6	Moderate	0%
Apple Valley	55,336	2.1 pCi/L	1.5	Moderate	0%
Edina	53,348	2.4 pCi/L	1.9	Moderate	0%
Minnetonka	52,463	2.5 pCi/L	2.0	Moderate	0%
St. Louis Park	49,697	2.4 pCi/L	1.8	Moderate	0%
Shakopee	47,158	2.4 pCi/L	1.8	Moderate	0%
Mankato	45,742	3.2 pCi/L	2.3	Moderate	0%
Moorhead	45,202	3.6 pCi/L	2.2	Moderate	0%

Highest-radon ZIP codes in Minnesota

The 10 Minnesota ZIP codes with the highest predicted basement average (model estimate), out of 829 modeled. A ZIP average is still an area figure - neighboring homes routinely test several pCi/L apart.

ZIP	County	Predicted basement	Upstairs	Grade
56721	Polk County	5.1 pCi/L	2.3	High
56171	Martin County	5.0 pCi/L	2.6	High
56156	Rock County	4.9 pCi/L	2.7	High
56138	Rock County	4.9 pCi/L	2.8	High
56172	Murray County	4.8 pCi/L	2.5	High
56128	Pipestone County	4.8 pCi/L	2.4	High
56277	Renville County	4.7 pCi/L	2.4	High
56150	Jackson County	4.7 pCi/L	2.5	High
56110	Nobles County	4.6 pCi/L	2.5	High
56178	Lincoln County	4.6 pCi/L	2.6	High

Minnesota radon questions

Is radon high in Minnesota?: Minnesota's population-weighted predicted basement average is 2.4 pCi/L, about 1.4× the US average of 1.8. 9 of its 87 modeled counties are predicted at or above the EPA action level of 4 pCi/L, 73 are in the 2-4 "consider fixing" range and 5 are below 2. 8.6% of Minnesota ZIP codes are predicted at 4 or higher.
Which Minnesota county has the highest radon?: Rock County has the highest predicted basement average in Minnesota at 4.7 pCi/L (EPA Zone 1). The lowest is Anoka County at 1.8 pCi/L. In measured state test data (2016-2025), Rock County has the largest share of results at or above 4 pCi/L (77.3%). These are area figures; individual homes in any county can test far higher.
How many EPA Zone 1 counties are in Minnesota?: 68 of Minnesota's 87 counties (78%) are EPA Zone 1 (highest potential), 19 are Zone 2 and 0 are Zone 3. The EPA zone map dates from 1993; the predicted values on this page come from a 2001-2021 model built on millions of actual tests, so the two can disagree for a given county.
Should I test for radon in Minnesota?: Yes - with some urgency. Minnesota's predicted average is in the moderate range, and 84.7% of its ZIP codes are predicted at 2 pCi/L or higher. A short-term charcoal kit or a continuous digital monitor will tell you your actual level within days.

Minnesota radon program

Minnesota's radon program page is at www.health.state.mn.us; it lists testing and certified-mitigator guidance for the state. The EPA also keeps a directory of every state radon contact: EPA state radon contacts page. Then read how to test and what mitigation costs.