Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Clark County, Nevada
EPA puts Clark County in Zone 3, its lowest radon zone, and most reported tests there come back low, though 8.1% of 2,598 (2008 to 2017, laboratory totals) reached 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
8.1%
14.7 pts below NV
- Clark
- 8.1%
- Nevada
- 22.8%
2,598 tests, 2008 to 2017
Median result
0.9pCi/L
Below action level
- Clark
- 0.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
2,598
2nd of 11 by tests
- Clark
- 2,598
- Washoe
- 5,046
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Rank in Nevada
11 of 11
Lowest quarter
- Clark
- 8.1%
- Carson City
- 40.6%
By share, of 11 with 30+ tests
Read a result for Clark County
Starts at Clark County's median, 0.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 0.9 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Clark County's median reported result, 2008 to 2017.
The data
Clark County, At a glance
Clark County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 62% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Clark County, 2008 to 2017, laboratory
Under 2 pCi/L: 80%2 to 4 pCi/L: 12%4 pCi/L and above: 8%
Of 2,598 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 2,074 | 79.8% |
| 2 to 4 pCi/L | 314 | 12.1% |
| 4 pCi/L and above | 210 | 8.1% |
What these figures count
These are the 2,598 tests reported to CDC for Clark County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Clark County, Compared
Clark County radon figures, compared
Calculated by Radon411Clark County reports fewer high tests than Nevada overall. 8.1% of its 2,598 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 14.7 points below the 22.8% pooled from 16 Nevada counties.
Ordered from highest share down, it comes 11th of 11 Nevada counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Clark County sits 27.6 points below it.
Next door, the shares run from 4.1% in Mohave County, AZ to 11.1% in Nye County, with San Bernardino County, CA and Mohave County, AZ below Clark County. Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 8.1% share point the same way here.
Half the tests came in under 0.9 pCi/L and half over it; the single highest reached 35.4 pCi/L. The rest split 79.8% under 2 pCi/L and 12.1% from 2 to 4 (Nevada: 52.5% and 24.8%).
CDC's ten-year totals for Clark County went from 1,810 tests (2005 to 2014) to 2,598 (2008 to 2017), the share going from 8.2% to 8.1%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Clark County, State data
Nevada's own radon test data
MeasuredWhat Nevada's own agencies publish about radon tests in Clark County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What the Nevada Radon Education Program reports for the ZIP codes in Clark County
The Nevada Radon Education Program publishes its figures by ZIP code, not by county. These are the 67 ZIP codes that lie wholly or partly in Clark County, each with the state's own figures for it. Period: 1989-2015.
| ZIP code | What the state reports |
|---|---|
| 89002 | average 1.6 pCi/L |
| 89005 | average 3.1 pCi/L |
| 89011 | average 1.6 pCi/L |
| 89012 | average 2.5 pCi/L |
| 89014 | average 1.9 pCi/L |
| 89015 | average 2.0 pCi/L |
| 89019 | average 2.2 pCi/L |
| 89021 | average 4.9 pCi/L |
| 89027 | average 1.9 pCi/L |
| 89029 | average 1.3 pCi/L |
| 89030 | average 3.9 pCi/L |
| 89031 | average 1.1 pCi/L |
| 89032 | average 4.7 pCi/L |
| 89034 | average 0.8 pCi/L |
| 89039 | average 0.8 pCi/L |
| 89040 | average 5.1 pCi/L |
| 89044 | average 2.1 pCi/L |
| 89052 | average 4.5 pCi/L |
| 89074 | average 2.1 pCi/L |
| 89081 | average 1.1 pCi/L |
| 89084 | average 1.3 pCi/L |
| 89085 | average 0.6 pCi/L |
| 89086 | average 2.5 pCi/L |
| 89101 | average 0.9 pCi/L |
| 89102 | average 2.1 pCi/L |
| 89103 | average 1.0 pCi/L |
| 89104 | average 1.9 pCi/L |
| 89106 | average 1.9 pCi/L |
| 89107 | average 1.0 pCi/L |
| 89108 | average 1.6 pCi/L |
| 89109 | average 1.3 pCi/L |
| 89110 | average 2.1 pCi/L |
| 89113 | average 1.4 pCi/L |
| 89115 | average 1.8 pCi/L |
| 89117 | average 0.9 pCi/L |
| 89118 | average 0.8 pCi/L |
| 89119 | average 1.0 pCi/L |
| 89120 | average 1.2 pCi/L |
| 89121 | average 1.6 pCi/L |
| 89122 | average 1.2 pCi/L |
| 89123 | average 1.1 pCi/L |
| 89124 | average 7.4 pCi/L |
| 89128 | average 0.8 pCi/L |
| 89129 | average 1.1 pCi/L |
| 89130 | average 1.0 pCi/L |
| 89131 | average 1.8 pCi/L |
| 89134 | average 1.0 pCi/L |
| 89135 | average 1.1 pCi/L |
| 89138 | average 0.7 pCi/L |
| 89139 | average 1.3 pCi/L |
| 89141 | average 1.2 pCi/L |
| 89142 | average 1.2 pCi/L |
| 89143 | average 1.1 pCi/L |
| 89144 | average 0.8 pCi/L |
| 89145 | average 1.0 pCi/L |
| 89146 | average 2.4 pCi/L |
| 89147 | average 0.8 pCi/L |
| 89148 | average 0.8 pCi/L |
| 89149 | average 1.2 pCi/L |
| 89156 | average 1.9 pCi/L |
| 89161 | average 1.9 pCi/L |
| 89166 | average 0.8 pCi/L |
| 89169 | average 1.0 pCi/L |
| 89178 | average 0.8 pCi/L |
| 89179 | average 0.9 pCi/L |
| 89183 | average 2.3 pCi/L |
| 89191 | average 0.8 pCi/L |
- NBMG says the results are based on independently tested homes, not scientific sampling.
- The service publishes an average for each ZIP code but no count of tests.
- Site specific testing is the only way to determine local radon concentrations.
- A ZIP code that crosses the county line is listed whole; its figures cover all of it.
Measured: Nevada Radon Education Program data, 1989-2015.
Clark County, Geology
The ground under Clark County
PredictedUSGS's geologic map splits Clark County: 62.3% of its land is low radon potential and 37.7% moderate. The map puts 37.0% of Clark County in the area it calls Great Basin and 30.1% in Great Basin, with 2 smaller areas beside them. USGS gives the first a radon index of 8, in the low band (5 to 8), and the second 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Great Basin | Sandstone, shale, limestone, mafic volcanic rocks. | Low | 8 | 37.0% |
| Great Basin | Sandstone, shale, limestone, mafic volcanic rocks. | Moderate | 11 | 30.1% |
| Basin and Range/Sonoran Desert | Quaternary to Tertiary sediments, with uranium-bearing Tertiary volcanic rocks, highly variable volcanic, metamorphic, and sedimentary rocks, and eolian deposits | Low | 8 | 25.2% |
| Colorado Plateau | Paleozoic sadstone, shale, and limestones, some Precambrian gneiss, metasedimentary rocks, granites. | Moderate | 9 | 7.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Clark County beside the ground around it
Across Nevada 17.3% of the land is rated high; none of Clark County's is. Of the 5 counties that border it, 3 have more high-potential ground, Lincoln County the most at 27.1%.
The map rates the ground, not the air in any home.
Local help
Clark County, Local resources
Radon testing and mitigation in Clark County
- Nevada Radon Education ProgramNevada Radon Education Program, run by University Of Nevada, Reno, offers free or discounted test kits, and answers questions about testing and mitigation in Nevada.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The program offers literature, maps, educational presentations and low-cost radon test kits.
- Compare kits
- Professionals in Nevada20 professionals are listed in Nevada.
What Nevada's program says
- chrisk@unr.edu
What it means
Clark County, Questions
Questions about radon in Clark County
Are radon levels high in Clark County?
Over the 2008 to 2017 laboratory totals, 8.1% of the radon tests reported to CDC for Clark County, Nevada were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.9 pCi/L. Of 11 Nevada counties with 30 or more tests for the same period, 10 reported a higher share; pooled, the state comes to 22.8%.
Which counties border Clark County?
Clark County borders 5 counties: Mohave County, AZ, San Bernardino County, CA, Lincoln County, NV, Inyo County, CA and Nye County, NV.
Products
Clark County, Products
Testing a home in Clark County
In Clark County, 8.1% of 2,598 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 22.8% pooled across Nevada. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Clark County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Monitor
EcoQube Flex battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 15 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Clark County, Bordering counties
Counties bordering Clark County
Calculated by Radon411- Radon levels in Inyo County, CAEPA zone 2
50.0%at or above 4 pCi/L
Median 4.0 pCi/L · 14 tests · 41.9 points above Clark County
- Radon levels in Lincoln County, NVEPA zone 1
25.0%at or above 4 pCi/L
Median 2.1 pCi/L · 12 tests · 16.9 points above Clark County
- Radon levels in Nye County, NVEPA zone 2
11.1%at or above 4 pCi/L
Median 1.3 pCi/L · 81 tests · 3.0 points above Clark County
4.5%at or above 4 pCi/L
Median 0.7 pCi/L · 178 tests · 3.6 points below Clark County
- Radon levels in Mohave County, AZEPA zone 2
4.1%at or above 4 pCi/L
Median 0.2 pCi/L · 49 tests · 4.0 points below Clark County
Clark County, Cities and towns
Cities and towns in Clark County
Clark County is growing: the Census Bureau puts it at 2,407,226 residents on July 1, 2025, up 5.8% from 2,275,833 in 2020. That works out to 305 people per square mile of land. Its largest town, Las Vegas, has 679,817 residents, 28.2% of the total. Together its 5 incorporated places hold 56.9% of those residents; the other 43.1% live outside any of them. Reported testing is thin here: 2,598 tests over 2008 to 2017, or 1.1 for every 1,000 residents (2025 estimate), where Nevada as a whole comes to 3.3.
From Las Vegas to Boulder City, CDC publishes no figure by town: each reads Clark County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Las Vegas | 679,817 | +5.0% | 28.2% |
| Henderson | 353,289 | +10.9% | 14.7% |
| North Las Vegas | 296,653 | +13.6% | 12.3% |
| Mesquite | 24,001 | +16.5% | 1.0% |
| Boulder City | 14,884 | −0.1% | 0.6% |
Places in Clark County with a city page: 1 of 1
5 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).
Clark County, Homes
Homes in Clark County
Of Clark County's 935,960 homes, 60% are detached houses, against 60% across Nevada; 24% are in buildings of five or more homes. Half of its homes were built before 1997, close to Nevada's 1996: 3% date from before 1960 and 43% from 2000 or later. 57% of occupied homes are lived in by their owner (Nevada: 59%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Clark County | Nevada |
|---|---|---|
| Housing units | 935,960 | 1,307,338 |
| Detached houses | 60% | 60% |
| In buildings of 5 or more | 24% | 22% |
| Mobile homes | 3% | 6% |
| Built before 1960 | 3% | 5% |
| Built since 2000 | 43% | 40% |
| Middle year built | 1997 | 1996 |
| Owner-occupied | 57% | 59% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.