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Wyoming Radon Map and Levels by County

Wyoming's counties span EPA Zones 1 and 2. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    44.3%

    8.5 pts above U.S.

    Wyoming
    44.3%
    U.S.
    35.7%

    7,638 tests across 23 counties, 2008 to 2017

  • Rank among states

    9 of 47

    Ten highest states

    Wyoming
    44.3%
    North Dakota
    59.3%

    By share, every state pooled the same way, 2008 to 2017

  • Counties in EPA Zone 1

    21 of 23

    Most at highest potential

    Zone 1
    21
    Zone 2
    2

    Most counties sit in Zone 1; Zone 1 is the highest potential

  • Highest county

    69.5%

    Sheridan County

    Sheridan
    69.5%
    Uinta
    24.6%

    Counties with 30+ tests, 2008 to 2017

Read a result for Wyoming

Starts at EPA's action level

4.0pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 4.0 pCi/L

At or above 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. 44.3% of Wyoming's reported tests reached 4 pCi/L, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Wyoming, At a glance

Wyoming at a glance

Predicted: EPA radon zone

23 of 23 counties classified

EPA classifies counties, not states. Of the 23 counties in Wyoming with a zone, 21 are in Zone 1 and 2 in Zone 2.

  • Zone 1: Highest predicted potentialgreater than 4 pCi/L21 of 23 counties · 91.3%
  • Zone 2: Moderate predicted potential2 to 4 pCi/L2 of 23 counties · 8.7%

An EPA radon zone predicts a whole county. It is not intended to determine whether any individual home should be tested: homes with elevated levels occur in all three zones, and EPA recommends testing every home regardless of zone.

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

CDC test figures, county by county

CDC publishes Wyoming's radon test figures by county: 23 of its 23 counties have one. Each one's share is in the county list.

How to read these figures

Wyoming, Compared

Wyoming radon figures, compared

Calculated by Radon411
Wyoming, 2008 to 2017, laboratory
44.3%
of 7,638 tests at or above 4 pCi/L, pooled
Against the U.S.
+8.5points
35.7% pooled
Rank among the states
9 of 47
1 is the highest share
Counties with 30 or more tests
22
Highest
69.5%
Sheridan County
Lowest
24.6%
Uinta County

Wyoming pools to 44.3%: that share of 7,638 reported tests from 23 counties over the 2008 to 2017 laboratory totals reached EPA's action level. Nationally the pooled share is 35.7%: 8.5 points lower than here.

Among 47 states pooled the same way it ranks 9th, with Montana (45.5%) above it and Kentucky (43.7%) below. Sheridan County reports the highest share (69.5% of 846 tests) and Uinta County the lowest (24.6%); the most tests came from Laramie County, 1,834 of them at 25.5%.

Across its 4 overlapping ten-year totals, the share went from 45.5% (2005 to 2014) to 44.3% (2008 to 2017), within 2 points, with 2005 to 2014 the highest at 45.5%. By band, 9 counties at 50% or more, 9 counties at 30% to 50%, 4 counties at 15% to 30%.

EPA's 1993 map puts 21 of its 23 classified counties in Zone 1; the tests reported since bear that out at 44.3%.

Wyoming ranked among 47 states by pooled share of tests at or above 4 pCi/L, 2008 to 2017, laboratory
StateRankCountiesTestsAt or above 4 pCi/L
Iowa4 of 479995,24558.5%
Ohio5 of 478898,84052.3%
Colorado6 of 476396,36747.0%
Wisconsin7 of 477268,10446.9%
Montana8 of 47519,89345.5%
Wyoming9 of 47237,63844.3%
Kentucky10 of 4712028,79343.7%
Minnesota11 of 4787130,91243.4%
Illinois12 of 47102108,90943.1%
Utah13 of 472828,34241.9%
Pennsylvania14 of 4767203,04541.7%
Wyoming's highest and lowest counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/L
Sheridan County1 of 2284669.5%
Lincoln County2 of 2214268.3%
Weston County3 of 223265.6%
Converse County4 of 2213062.3%
Crook County5 of 225158.8%
Hot Springs County6 of 225955.9%
Natrona County7 of 221,05455.7%
Fremont County8 of 2261855.7%
Sublette County9 of 226050.0%
Sweetwater County10 of 2240949.6%
Uinta County22 of 2219924.6%
Laramie County21 of 221,83425.5%
Platte County20 of 2213226.5%
Albany County19 of 2239427.9%
Johnson County18 of 2213534.8%
Wyoming's counties with 30 or more tests, by their own share at or above 4 pCi/L, 2008 to 2017, laboratory
ShareCountiesTheir testsFor example
50% or more92,992Sheridan County, Lincoln County, Weston County
30% to 50%92,075Sweetwater County, Teton County, Campbell County
15% to 30%42,559Albany County, Platte County, Laramie County
5% to 15%00None
Under 5%00None
Wyoming ten-year laboratory totals, pooled, against the United States
PeriodCountiesTestsAt or above 4 pCi/LUnited StatesChange from the row before
2008 to 2017237,63844.3%35.7%−0.4 points
2007 to 2016237,48444.6%35.8%−0.6 points
2006 to 2015237,32345.3%36.3%−0.2 points
2005 to 2014237,49245.5%36.0%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period. CDC publishes no state or national figure.

Wyoming, Counties

Wyoming counties by EPA zone

Predicted

All 23 counties, grouped by the zone EPA predicts and ordered by their reported share at or above 4 pCi/L, under Wyoming's map. Each county has a page of its own.

Wyoming radon map by county: EPA radon zones. Map of Wyoming's 23 counties shaded by EPA radon zone: Zone 1 in red-orange, Zone 2 in amber. 21 in Zone 1, 2 in Zone 2, 0 in Zone 3.
Wyoming radon map by countyEPA radon zones for Wyoming's counties: 21 counties in Zone 1, 2 counties in Zone 2, 0 counties in Zone 3.A prediction for each county, not a reading of any home; elevated homes occur in all three zones.

The 12 highest in Wyoming, 2008 to 2017

Zone 1: highest predicted potential21

Local help

Wyoming, Local resources

Local resources in Wyoming

Who to ask in Wyoming: its radon program, test kits and professionals.

What it means

Wyoming, Questions

Questions about radon in Wyoming

Is radon a problem in Wyoming?

Of the 23 counties in Wyoming that EPA's Map of Radon Zones classifies, 21 carry Zone 1 (the highest predicted potential), 2 Zone 2 and 0 Zone 3. Pooled from 23 counties, 44.3% of the 7,638 radon tests reported to CDC over the 2008 to 2017 laboratory totals were at or above 4 pCi/L, 9th of 47 states.

Who does radon mitigation in Wyoming?

2 radon businesses are listed for Wyoming, for testing, mitigation or both; each listing names the licensing list it was read from.

Which Wyoming counties are in EPA radon Zone 1?

Zone 1 holds 21 counties in Wyoming; the first 8 by name are Albany County, Big Horn County, Campbell County, Carbon County, Converse County, Crook County, Fremont County, Goshen County, the rest in the county table on this page.

Which Wyoming counties have the highest radon?

Sheridan County 69.5% (846 tests) leads Wyoming by the share of reported tests at or above 4 pCi/L, 2008 to 2017, laboratory, then Lincoln County 68.3% (142 tests), Weston County 65.6% (32 tests), Converse County 62.3% (130 tests), Crook County 58.8% (51 tests).

Which EPA region is Wyoming in?

Wyoming is in EPA Region 8: Mountains and Plains.

Products

Wyoming, Products

Testing a home in Wyoming

44.3% of the 7,638 tests reported to CDC for Wyoming over the 2008 to 2017 laboratory totals reached 4 pCi/L: a short-term kit (2 to 90 days) gives a first answer in days, a long-term test the year-round average. A short-term kit (2 to 90 days) is the quick first check for a home in Wyoming; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Wyoming homes, compared

Explore

Cities in Wyoming with their own page

Radon data is published by county, not by city. Each city page sets the figures of the counties the city lies in side by side.