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Radon Levels in Cochise County, Arizona

EPA puts Cochise County in Zone 2, its middle radon zone, and only 26 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). 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

    21.2%

    3.8 pts above AZ

    Cochise
    21.2%
    Arizona
    17.4%

    33 tests, 2005 to 2014

  • Median result

    2.7pCi/L

    Below action level

    Cochise
    2.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2005 to 2014

  • Tests reported

    33

    7th of 7 by tests

    Cochise
    33
    Maricopa
    2,101

    Reported to CDC before any fix, 2005 to 2014

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Arizona

    2 of 7

    Top quarter

    Cochise
    21.2%
    Coconino
    38.1%

    By share, of 7 with 30+ tests

Read a result for Cochise County

Starts at Cochise County's median, 2.7 pCi/L

2.7pCi/L

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

EPA’s reading of 2.7 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Cochise County's median reported result, 2005 to 2014.

Interpret this readingWhat a fix costs

The data

Cochise County, At a glance

Cochise County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Cochise County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

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

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Cochise County, 2008 to 2017, laboratory

CDC holds 26 reported tests for Cochise County over the 2008 to 2017 laboratory totals, with a median of 2.8 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Cochise County beside the counties around it is how this page reads it.

What these figures count

Only 26 tests were reported to CDC for Cochise County over 2008 to 2017 (laboratory totals), and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.

Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Cochise County, Compared

Cochise County radon figures, compared

Calculated by Radon411

Cochise County's 33 reported tests over the 2005 to 2014 laboratory totals had a middle value of 2.7 pCi/L and a maximum of 18.5 pCi/L, and 21.2% reached 4 pCi/L. Arizona as a whole (12 Arizona counties, pooled) comes to 17.4%: 3.8 points lower than here.

The newest figure, over the 2008 to 2017 laboratory totals, counts only 26 tests (26.9% at or above 4 pCi/L), too few to compare, so this reading uses the 33-test figure.

Among its state's counties it ranks 2nd of 7 Arizona counties with 30 or more tests for the same period. Statewide for the same period, Coconino County reported the highest share (38.1%) and Mohave County the lowest (4.3%).

Below the action level, 16 tests (48.5%) came in under 2 pCi/L, against 60.3% statewide, and 10 tests (30.3%) fell between 2 and 4, against 22.3% statewide. CDC's ten-year totals for Cochise County went from 33 tests (2005 to 2014) to 26 (2008 to 2017), the share going from 21.2% to 26.9%.

EPA's 1993 zone map puts Cochise County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land low radon potential.

Pima County, the one bordering county with a figure for the same period, reported 5.7%.

Cochise County against Arizona, the United States and nearby counties, 2005 to 2014, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Cochise County
Cochise County3321.2%2.7 pCi/LThis county
Arizona, pooled12 counties, pooled3,04417.4%Not pooled−3.8 points
United States, pooled2,655 counties, pooled1,669,35336.0%Not pooled+14.8 points
Coconino Countyhighest in the state18138.1%2.5 pCi/L+16.9 points
Mohave Countylowest in the state474.3%0.2 pCi/L−16.9 points
Graham County, AZborders it944.4%3.0 pCi/L+23.2 points
Pima County, AZborders it3365.7%1.1 pCi/L−15.5 points
Santa Cruz County, AZborders it110.0%1.5 pCi/L−21.2 points
Where Cochise County's reported results fell, 2005 to 2014, laboratory, beside Arizona and the United States
ResultCochise County testsCochise County shareArizona shareU.S. shareAgainst Arizona
Under 2 pCi/L1648.5%60.3%39.8%−11.8 points
2 to 4 pCi/L1030.3%22.3%24.2%+8.0 points
4 pCi/L and above721.2%17.4%36.0%+3.8 points
Cochise County ranked among the 7 Arizona counties with 30 or more tests, by share at or above 4 pCi/L, 2005 to 2014, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Coconino County1 of 718138.1%2.5 pCi/L
Cochise County2 of 73321.2%2.7 pCi/L
Yavapai County3 of 720018.5%1.7 pCi/L
Maricopa County4 of 72,10117.9%1.6 pCi/L
Pinal County5 of 7868.1%0.8 pCi/L
Pima County6 of 73365.7%1.1 pCi/L
Mohave County7 of 7474.3%0.2 pCi/L
Cochise County ten-year laboratory totals, against Arizona's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestArizona, pooledChange from the row before
2008 to 20172626.9%2.8 pCi/L18.5 pCi/L16.8%Level
2007 to 20162626.9%2.8 pCi/L18.5 pCi/L16.5%−0.4 points
2006 to 20152227.3%3.0 pCi/L18.5 pCi/L17.6%+6.1 points
2005 to 20143321.2%2.7 pCi/L18.5 pCi/L17.4%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Cochise County, Geology

The ground under Cochise County

Predicted

Most of the ground under Cochise County is one class on USGS's geologic map: 99.7% of its land is low radon potential, with 0.3% moderate. All of it lies in the area the map calls Basin and Range/Sonoran Desert, to which USGS gives a radon index of 8, in the low band (5 to 8).

USGS's geologic areas under Cochise County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Basin and Range/Sonoran DesertQuaternary to Tertiary sediments, with uranium-bearing Tertiary volcanic rocks, highly variable volcanic, metamorphic, and sedimentary rocks, and eolian depositsLow899.7%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Cochise County beside the ground around it

Across Arizona 0.1% of the land is rated high; none of Cochise County's is. Of the 5 counties that border it, 3 have more moderate-potential ground, Greenlee County the most at 97.7%.

Share of land by USGS radon potential: Cochise County, the 5 counties bordering it and Arizona
AreaEPA zoneLow potentialModerate potentialHigh potential
Cochise CountyZone 299.7%0.3%None
Hidalgo County, NMZone 295.6%4.3%None
Graham CountyZone 229.6%70.4%None
Santa Cruz CountyZone 2100%NoneNone
Greenlee CountyZone 22.3%97.7%None
Pima CountyZone 2100%NoneNone
Arizona15 counties, pooled by land areaVaries42.8%57.1%0.1%

The map rates the ground, not the air in any home.

Local help

Cochise County, Local resources

Radon testing and mitigation in Cochise County

What it means

Cochise County, Questions

Questions about radon in Cochise County

Are radon levels high in Cochise County?

Over the 2008 to 2017 laboratory totals, 26.9% of the radon tests reported to CDC for Cochise County, Arizona were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.8 pCi/L. Of 7 Arizona counties with 30 or more tests for the same period, 1 reported a higher share; pooled, the state comes to 17.4%.

Which counties border Cochise County?

Cochise County borders 5 counties: Hidalgo County, NM, Graham County, AZ, Santa Cruz County, AZ, Greenlee County, AZ and Pima County, AZ.

Products

Cochise County, Products

Testing a home in Cochise County

In Cochise County, 21.2% of 33 tests reported to CDC over the 2005 to 2014 laboratory totals reached 4 pCi/L, against 17.4% pooled across Arizona. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Cochise County; a long-term test tells the year-round average.

Test kits and monitors3

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Best radon monitors for Cochise County homes, compared

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Cochise County, Bordering counties

Counties bordering Cochise County

Calculated by Radon411

Cochise County, Cities and towns

Cities and towns in Cochise County

The Census Bureau estimates 126,332 residents in Cochise County for July 1, 2025, 805 more than in 2020 (+0.6%). That works out to 20 people per square mile of land. Its largest town, Sierra Vista, has 44,907 residents, 35.5% of the total. Together its 7 incorporated places hold 61.3% of those residents; the other 38.7% live outside any of them. Reported testing is thin here: 33 tests over 2005 to 2014, or 0.3 for every 1,000 residents (2025 estimate), where Arizona as a whole comes to 0.4.

From Sierra Vista to Tombstone, CDC publishes no figure by town: each reads Cochise County's.

The cities and towns in Cochise County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Sierra Vista44,907−1.0%35.5%
Douglas16,038−2.9%12.7%
Benson5,532+2.2%4.4%
Bisbee4,860−1.2%3.8%
Willcox3,189−1.2%2.5%
Huachuca City1,583−2.6%1.3%
Tombstone1,376+5.3%1.1%

7 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).

Cochise County, Homes

Homes in Cochise County

Of Cochise County's 59,312 homes, 66% are detached houses, against 64% across Arizona; 20% are mobile homes. Half of its homes were built before 1986, close to Arizona's 1992: 15% date from before 1960 and 27% from 2000 or later. 71% of occupied homes are lived in by their owner (Arizona: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Cochise County, Arizona, 2019 to 2023
HomesCochise CountyArizona
Housing units59,3123,142,443
Detached houses66%64%
In buildings of 5 or more9%16%
Mobile homes20%10%
Built before 196015%8%
Built since 200027%35%
Middle year built19861992
Owner-occupied71%67%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.