Radon Levels By State

Average Radon Level
Average Radon Level
1.AlaskaAlaska10.7
2.South DakotaSouth Dakota9.6
3.PennsylvaniaPennsylvania8.6
4.OhioOhio7.8
5.WashingtonWashington7.5
6.MontanaMontana7.4
7.KentuckyKentucky7.4
8.IdahoIdaho7.3
9.ColoradoColorado6.8
10.IowaIowa6.1
11.West VirginiaWest Virginia6.1
12.North DakotaNorth Dakota6.0
13.MaineMaine5.9
14.WisconsinWisconsin5.7
15.New HampshireNew Hampshire5.6
16.MarylandMaryland5.4
17.IllinoisIllinois5.3
18.NebraskaNebraska5.2
19.WyomingWyoming5.0
20.KansasKansas4.9
21.TennesseeTennessee4.8
22.IndianaIndiana4.7
23.MinnesotaMinnesota4.6
24.New JerseyNew Jersey4.4
25.UtahUtah4.4
26.MissouriMissouri4.3
27.Rhode IslandRhode Island4.3
28.New YorkNew York4.2
29.North CarolinaNorth Carolina4.0
30.AlabamaAlabama3.9
31.MassachusettsMassachusetts3.9
32.New MexicoNew Mexico3.9
33.VermontVermont3.7
34.VirginiaVirginia3.6
35.MichiganMichigan3.5
36.ConnecticutConnecticut3.4
37.NevadaNevada3.4
38.OregonOregon3.1
39.ArkansasArkansas2.5
40.OklahomaOklahoma2.5
41.DelawareDelaware2.4
42.South CarolinaSouth Carolina2.4
43.CaliforniaCalifornia2.3
44.GeorgiaGeorgia2.3
45.TexasTexas2.1
46.ArizonaArizona1.9
47.FloridaFlorida1.8
48.MississippiMississippi1.2
49.LouisianaLouisiana1.1

Tracking Radon Across States

Radon, a stealthy and naturally occurring radioactive gas, is prevalent across the United States, silently contributing to a significant share of lung cancer cases nationwide. With no smell, taste, or color, it quietly infiltrates our homes, originating from the decay of uranium in soil, rock, and water. Prolonged exposure to this silent menace has long-term health implications, making it essential to evaluate and monitor average radon levels in every state. The U.S. Environmental Protection Agency (EPA) recommends taking action if radon levels exceed 4 pCi/L in homes. To provide a comprehensive overview of radon distribution in the U.S, we've collated data from various states, ranking each according to their average radon level in picocuries per liter (pCi/L), a measure of radioactivity.

  • Alaska leads the list as the state with the highest average radon level of 10.7 pCi/L, significantly above the EPA's recommended action level. Following Alaska, South Dakota and Pennsylvania also report alarmingly high radon levels of 9.6 and 8.6 pCi/L, respectively.
  • Interestingly, the top ten states with the highest radon levels are a combination of both coastal and inland states, debunking any presumptions of geographical favoritism.
  • On the flip side, Louisiana records the lowest average radon level of 1.1 pCi/L, followed by Mississippi and Florida. It's noteworthy that the three states with the lowest radon levels are all in the Southern U.S.
  • From the middle to the lower end of the spectrum, average radon levels remain fairly consistent, hovering around the 4 pCi/L mark. This concentration range includes states like North Carolina, Nevada, and Oregon.

States with the Highest Radon Levels

When evaluating the states with the highest average radon levels, Alaska grabs the top spot, with an average of 10.7 pCi/L. In the second position, we have South Dakota, exhibiting a high average radon level of 9.6 pCi/L. Next comes Pennsylvania, with a radon level of 8.6 pCi/L.Following closely, Ohio secures the fourth position with an average radon level of 7.8 pCi/L outperforming the fifth spot, Washington, which sees a 7.5 pCi/L radon level. Montana and Kentucky both present a joint average of 7.4 pCi/L of radon, posing significant health risks to their residents. Idaho's radon level is not far behind, standing at 7.3 pCi/L and surpassing Colorado's level of 6.8 pCi/L. Lastly, Iowa closes our top ten list, having an average radon level of 6.1 pCi/L which, although lower, still is above the EPA's recommended radon action level. States with the Highest Radon Levels:

  1. Alaska - 10.7 pCi/L
  2. South Dakota - 9.6 pCi/L
  3. Pennsylvania - 8.6 pCi/L
  4. Ohio - 7.8 pCi/L
  5. Washington - 7.5 pCi/L
  6. Montana - 7.4 pCi/L
  7. Kentucky - 7.4 pCi/L
  8. Idaho - 7.3 pCi/L
  9. Colorado - 6.8 pCi/L
  10. Iowa - 6.1 pCi/L

By Region

Alabama

See Less
Alabama

Metric

Value

Rank

Average Radon Level

3.9

#30

Alaska

See More
Alaska

Metric

Value

Rank

Average Radon Level

10.7

#1

Arizona

See More
Arizona

Metric

Value

Rank

Average Radon Level

1.9

#46

Arkansas

See More
Arkansas

Metric

Value

Rank

Average Radon Level

2.5

#39

California

See More
California

Metric

Value

Rank

Average Radon Level

2.3

#43

Colorado

See More
Colorado

Metric

Value

Rank

Average Radon Level

6.8

#9

Connecticut

See More
Connecticut

Metric

Value

Rank

Average Radon Level

3.4

#36

Delaware

See More
Delaware

Metric

Value

Rank

Average Radon Level

2.4

#41

Florida

See More
Florida

Metric

Value

Rank

Average Radon Level

1.8

#47

Georgia

See More
Georgia

Metric

Value

Rank

Average Radon Level

2.3

#44

Idaho

See More
Idaho

Metric

Value

Rank

Average Radon Level

7.3

#8

Illinois

See More
Illinois

Metric

Value

Rank

Average Radon Level

5.3

#17

Indiana

See More
Indiana

Metric

Value

Rank

Average Radon Level

4.7

#22

Iowa

See More
Iowa

Metric

Value

Rank

Average Radon Level

6.1

#10

Kansas

See More
Kansas

Metric

Value

Rank

Average Radon Level

4.9

#20

Kentucky

See More
Kentucky

Metric

Value

Rank

Average Radon Level

7.4

#7

Louisiana

See More
Louisiana

Metric

Value

Rank

Average Radon Level

1.1

#49

Maine

See More
Maine

Metric

Value

Rank

Average Radon Level

5.9

#13

Maryland

See More
Maryland

Metric

Value

Rank

Average Radon Level

5.4

#16

Massachusetts

See More
Massachusetts

Metric

Value

Rank

Average Radon Level

3.9

#31

Michigan

See More
Michigan

Metric

Value

Rank

Average Radon Level

3.5

#35

Minnesota

See More
Minnesota

Metric

Value

Rank

Average Radon Level

4.6

#23

Mississippi

See More
Mississippi

Metric

Value

Rank

Average Radon Level

1.2

#48

Missouri

See More
Missouri

Metric

Value

Rank

Average Radon Level

4.3

#26

Montana

See More
Montana

Metric

Value

Rank

Average Radon Level

7.4

#6

Nebraska

See More
Nebraska

Metric

Value

Rank

Average Radon Level

5.2

#18

Nevada

See More
Nevada

Metric

Value

Rank

Average Radon Level

3.4

#37

New Hampshire

See More
New Hampshire

Metric

Value

Rank

Average Radon Level

5.6

#15

New Jersey

See More
New Jersey

Metric

Value

Rank

Average Radon Level

4.4

#24

New Mexico

See More
New Mexico

Metric

Value

Rank

Average Radon Level

3.9

#32

New York

See More
New York

Metric

Value

Rank

Average Radon Level

4.2

#28

North Carolina

See More
North Carolina

Metric

Value

Rank

Average Radon Level

4.0

#29

North Dakota

See More
North Dakota

Metric

Value

Rank

Average Radon Level

6.0

#12

Ohio

See More
Ohio

Metric

Value

Rank

Average Radon Level

7.8

#4

Oklahoma

See More
Oklahoma

Metric

Value

Rank

Average Radon Level

2.5

#40

Oregon

See More
Oregon

Metric

Value

Rank

Average Radon Level

3.1

#38

Pennsylvania

See More
Pennsylvania

Metric

Value

Rank

Average Radon Level

8.6

#3

Rhode Island

See More
Rhode Island

Metric

Value

Rank

Average Radon Level

4.3

#27

South Carolina

See More
South Carolina

Metric

Value

Rank

Average Radon Level

2.4

#42

South Dakota

See More
South Dakota

Metric

Value

Rank

Average Radon Level

9.6

#2

Tennessee

See More
Tennessee

Metric

Value

Rank

Average Radon Level

4.8

#21

Texas

See More
Texas

Metric

Value

Rank

Average Radon Level

2.1

#45

Utah

See More
Utah

Metric

Value

Rank

Average Radon Level

4.4

#25

Vermont

See More
Vermont

Metric

Value

Rank

Average Radon Level

3.7

#33

Virginia

See More
Virginia

Metric

Value

Rank

Average Radon Level

3.6

#34

Washington

See More
Washington

Metric

Value

Rank

Average Radon Level

7.5

#5

West Virginia

See More
West Virginia

Metric

Value

Rank

Average Radon Level

6.1

#11

Wisconsin

See More
Wisconsin

Metric

Value

Rank

Average Radon Level

5.7

#14

Wyoming

See More
Wyoming

Metric

Value

Rank

Average Radon Level

5.0

#19

Table

Region ↕Average Radon Level ↕
Alabama iconAlabama3.9
Alaska iconAlaska10.7
Arizona iconArizona1.9
Arkansas iconArkansas2.5
California iconCalifornia2.3
Colorado iconColorado6.8
Connecticut iconConnecticut3.4
Delaware iconDelaware2.4
Florida iconFlorida1.8
Georgia iconGeorgia2.3
Idaho iconIdaho7.3
Illinois iconIllinois5.3
Indiana iconIndiana4.7
Iowa iconIowa6.1
Kansas iconKansas4.9
Kentucky iconKentucky7.4
Louisiana iconLouisiana1.1
Maine iconMaine5.9
Maryland iconMaryland5.4
Massachusetts iconMassachusetts3.9
Michigan iconMichigan3.5
Minnesota iconMinnesota4.6
Mississippi iconMississippi1.2
Missouri iconMissouri4.3
Montana iconMontana7.4
Nebraska iconNebraska5.2
Nevada iconNevada3.4
New Hampshire iconNew Hampshire5.6
New Jersey iconNew Jersey4.4
New Mexico iconNew Mexico3.9
New York iconNew York4.2
North Carolina iconNorth Carolina4.0
North Dakota iconNorth Dakota6.0
Ohio iconOhio7.8
Oklahoma iconOklahoma2.5
Oregon iconOregon3.1
Pennsylvania iconPennsylvania8.6
Rhode Island iconRhode Island4.3
South Carolina iconSouth Carolina2.4
South Dakota iconSouth Dakota9.6
Tennessee iconTennessee4.8
Texas iconTexas2.1
Utah iconUtah4.4
Vermont iconVermont3.7
Virginia iconVirginia3.6
Washington iconWashington7.5
West Virginia iconWest Virginia6.1
Wisconsin iconWisconsin5.7
Wyoming iconWyoming5.0
Keep reading

Additional Miscellaneous Datasets

Raising Canes By State

Raising Canes By State

Renewable Energy Generation By Country

Renewable Energy Generation By Country

Richest Cities in the U.S.
Miscellaneous
U.S. Cities

Richest Cities in the U.S.

Richest States In USA

Richest States In USA

Right to Work States

Right to Work States

Russian Speaking Countries

Russian Speaking Countries