What does this radon potential ranking show?

It orders states by EPA radon potential zone. It is a comparison of this one published measure, not an overall ranking of where to live.

Where do these figures come from?

U.S. Environmental Protection Agency, Map of Radon Zones supplies this measure. States without a comparable published value are shown as not ranked rather than estimated.

How should I use this ranking?

Use it to narrow a search, then open a state or county profile for the underlying figures, source dates and caveats. A statewide number may not describe every neighbourhood.

Highest radon potential by state

EPA radon potential zone.

This measure has no better end. The order describes the states, it does not rank them — see the other direction.

EPA county screening guidance, not a measurement for any individual home. Zone 1 is the highest potential and average indoor levels may exceed 4 pCi/L; Zone 2 is moderate, roughly 2–4 pCi/L; Zone 3 is lower, below 2 pCi/L. State profiles show the most-populous official county zone; the U.S. view shows the population-weighted share of residents in the selected zone. County shading identifies counties in that zone. EPA says all homes should be tested, regardless of zone.

How to read this ranking

Iowa has the highest published radon potential in this comparison, at Zone 100. The next states shown are North Dakota (Zone 100) and Colorado (Zone 98).

The table orders 51 states by epa radon potential zone. It describes one published measure, not an overall judgment about where to live.

Use the result as a starting point, then compare the underlying source, dates, and local county figures before making a decision. EPA county screening guidance, not a measurement for any individual home. Zone 1 is the highest potential and average indoor levels may exceed 4 pCi/L; Zone 2 is moderate, roughly 2–4 pCi/L; Zone 3 is lower, below 2 pCi/L. State profiles show the most-populous official county zone; the U.S. view shows the population-weighted share of residents in the selected zone. County shading identifies counties in that zone. EPA says all homes should be tested, regardless of zone.

1IowaZone 100
2North DakotaZone 100
3ColoradoZone 98
4WyomingZone 97
5MaineZone 89
6MontanaZone 84
7NebraskaZone 83
8MinnesotaZone 81
9PennsylvaniaZone 77
10South DakotaZone 72
11IndianaZone 72
12ConnecticutZone 67
13OhioZone 63
14KansasZone 55
15MarylandZone 52
16TennesseeZone 52
17MassachusettsZone 47
18KentuckyZone 45
19New MexicoZone 45
20VirginiaZone 44
21WisconsinZone 42
22West VirginiaZone 39
23GeorgiaZone 33
24Rhode IslandZone 27
25IllinoisZone 27
26New JerseyZone 24
27IdahoZone 24
28New YorkZone 23
29AlabamaZone 23
30MissouriZone 22
31WashingtonZone 15
32MichiganZone 12
33South CarolinaZone 10
34NevadaZone 6
35North CarolinaZone 6
36UtahZone 4
37New HampshireZone 4
38CaliforniaZone 3
39AlaskaZone 0
40ArkansasZone 0
41ArizonaZone 0
42District of ColumbiaZone 0
43DelawareZone 0
44FloridaZone 0
45HawaiiZone 0
46LouisianaZone 0
47MississippiZone 0
48OklahomaZone 0
49OregonZone 0
50TexasZone 0
51VermontZone 0

Related place rankings

Frequently asked questions

What does this ranking show?: It orders states by EPA radon potential zone. It is one measure, not an overall verdict on where to live.
Where do the figures come from?: U.S. Environmental Protection Agency, Map of Radon Zones. States without a comparable published figure are listed as not ranked rather than estimated.
How should I use it?: Use it to narrow your search, then open a state or county profile for the source date, caveats and local context.

Put this map on your own site

Free to use. The chart names its source and links back, so it stays honest wherever it ends up.

<iframe src="https://movermath.com/embed/radon-potential" width="100%" height="420" style="border:0" loading="lazy" title="EPA radon potential zone by state"></iframe>

Source: U.S. Environmental Protection Agency, Map of Radon Zones. · How this is built

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