Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Washoe County, Nevada
EPA puts Washoe County in Zone 2, its middle radon zone, and 22.2% of its 5,046 reported radon tests (2008 to 2017, laboratory totals) were at or above 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
22.2%
0.6 pts below NV
- Washoe
- 22.2%
- Nevada
- 22.8%
5,046 tests, 2008 to 2017
Median result
1.9pCi/L
Below action level
- Washoe
- 1.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
5,046
Most tested in Nevada
- Washoe
- 5,046
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Nevada
7 of 11
Middle half
- Washoe
- 22.2%
- Carson City
- 40.6%
By share, of 11 with 30+ tests
Read a result for Washoe County
Starts at Washoe County's median, 1.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.9 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. Washoe County's median reported result, 2008 to 2017.
The data
Washoe County, At a glance
Washoe County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Washoe County is a
USGS geologic potential: Moderate across 58% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Washoe County, 2008 to 2017, laboratory
Under 2 pCi/L: 52%2 to 4 pCi/L: 26%4 pCi/L and above: 22%
Of 5,046 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 2,612 | 51.8% |
| 2 to 4 pCi/L | 1,312 | 26.0% |
| 4 pCi/L and above | 1,122 | 22.2% |
What these figures count
These are the 5,046 tests reported to CDC for Washoe 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).
Washoe County, Compared
Washoe County radon figures, compared
Calculated by Radon411Washoe County's 5,046 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.9 pCi/L and a maximum of 165.8 pCi/L, and 22.2% reached 4 pCi/L. Nevada as a whole (16 Nevada counties, pooled) comes to 22.8%: 0.6 points higher than here.
Among its state's counties it ranks 7th of 11 Nevada counties with 30 or more tests for the same period. Statewide for the same period, Carson City reported the highest share (40.6%) and Clark County the lowest (8.1%).
Below the action level, 2,612 tests (51.8%) came in under 2 pCi/L, against 52.5% statewide, and 1,312 tests (26.0%) fell between 2 and 4, against 24.8% statewide. CDC's ten-year totals for Washoe County went from 4,031 tests (2005 to 2014) to 5,046 (2008 to 2017), the share going from 21.5% to 22.2%.
EPA's 1993 zone map puts Washoe County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 58% of the county's land moderate radon potential.
Next door, the shares run from 7.4% in Placer County, CA to 40.6% in Carson City, with Storey County, Churchill County and Placer County, CA below Washoe County.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Washoe County, State data
Nevada's own radon test data
MeasuredWhat Nevada's own agencies publish about radon tests in Washoe 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 Washoe County
The Nevada Radon Education Program publishes its figures by ZIP code, not by county. These are the 25 ZIP codes that lie wholly or partly in Washoe County, each with the state's own figures for it. Period: 1989-2015.
| ZIP code | What the state reports |
|---|---|
| 89402 | average 4.1 pCi/L |
| 89405 | average 1.3 pCi/L |
| 89412 | average 4.2 pCi/L |
| 89431 | average 2.9 pCi/L |
| 89433 | average 1.7 pCi/L |
| 89434 | average 1.5 pCi/L |
| 89436 | average 2.0 pCi/L |
| 89439 | average 10.2 pCi/L |
| 89441 | average 2.8 pCi/L |
| 89442 | average 2.7 pCi/L |
| 89451 | average 4.2 pCi/L |
| 89501 | average 7.2 pCi/L |
| 89502 | average 2.9 pCi/L |
| 89503 | average 2.6 pCi/L |
| 89506 | average 2.2 pCi/L |
| 89508 | average 3.2 pCi/L |
| 89509 | average 5.7 pCi/L |
| 89510 | average 5.7 pCi/L |
| 89511 | average 3.8 pCi/L |
| 89512 | average 3.4 pCi/L |
| 89519 | average 2.2 pCi/L |
| 89521 | average 2.0 pCi/L |
| 89523 | average 2.2 pCi/L |
| 89703 | average 6.1 pCi/L |
| 89704 | average 4.2 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.
Washoe County, Geology
The ground under Washoe County
PredictedUSGS's geologic map splits Washoe County: 57.9% of its land is moderate radon potential and 42.1% low. The map puts 42.1% of Washoe County in the area it calls Modoc Plateau and 26.1% in Great Basin, with 3 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 |
|---|---|---|---|---|
| Modoc Plateau | Tertiary basalt flows, upper Tertiary to Quaternary basalt flows, and lesser amounts of andesite and rhyolite. | Low | 8 | 42.1% |
| Great Basin | Sandstone, shale, limestone, mafic volcanic rocks. | Moderate | 11 | 26.1% |
| Northern Basin and Range | Basalt, andesite, rhyolite, tuffaceous sandstone. Low uranium in the western part, uranium-bearing volcanic rocks and uranium deposits in the eastern part of the province. | Moderate | 9 | 18.7% |
| Sierra Nevada | Northern Sierra Nevada is underlain primarily by Paleozoic and Mesozoic metamorphic rocks. Granitic rocks predominate in the southern Sierrra Nevada , with lesser Mesozoic metamorphic rocks. | Moderate | 9 | 11.5% |
| Northern Basin and Range | Precambrian metamorphic rocks, late Precambrian and Paleozoic metamorphosed and unmetamorphosed sedimentary rocks, Mesozoic and Tertiary intrusive rocks, and Tertiary sedimentary and volcanic rocks. | Moderate | 9 | 1.5% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Washoe County beside the ground around it
Across Nevada 17.3% of the land is rated high; none of Washoe County's is. Of the 13 counties that border it, 4 have more high-potential ground, Humboldt County the most at 25.2%.
The map rates the ground, not the air in any home.
Local help
Washoe County, Local resources
Radon testing and mitigation in Washoe 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
Washoe County, Questions
Questions about radon in Washoe County
Are radon levels high in Washoe County?
Over the 2008 to 2017 laboratory totals, 22.2% of the radon tests reported to CDC for Washoe County, Nevada were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.9 pCi/L. Of 11 Nevada counties with 30 or more tests for the same period, 6 reported a higher share; pooled, the state comes to 22.8%.
Which counties border Washoe County?
Washoe County borders 13 counties: Lassen County, CA, Pershing County, NV, Storey County, NV, Sierra County, CA, Modoc County, CA, Humboldt County, NV, Carson City, NV, Churchill County, NV, Lyon County, NV, Nevada County, CA, Placer County, CA, Lake County, OR and Harney County, OR.
Products
Washoe County, Products
Testing a home in Washoe County
In Washoe County, 22.2% of 5,046 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 22.8% pooled across Nevada. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Washoe County; a long-term test tells the year-round average.
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
MonitorAranet
Radon One 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 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Washoe County, Bordering counties
Counties bordering Washoe County
Calculated by Radon411- Radon levels in Pershing County, NVEPA zone 1
52.0%at or above 4 pCi/L
Median 4.2 pCi/L · 25 tests · 29.8 points above Washoe County
- Radon levels in Carson City, NVEPA zone 1
40.6%at or above 4 pCi/L
Median 3.3 pCi/L · 731 tests · 18.4 points above Washoe County
- Radon levels in Humboldt County, NVEPA zone 2
32.3%at or above 4 pCi/L
Median 2.3 pCi/L · 65 tests · 10.1 points above Washoe County
- Radon levels in Lyon County, NVEPA zone 1
30.4%at or above 4 pCi/L
Median 2.6 pCi/L · 303 tests · 8.2 points above Washoe County
- Radon levels in Nevada County, CAEPA zone 2
25.0%at or above 4 pCi/L
Median 2.0 pCi/L · 260 tests · 2.8 points above Washoe County
- Radon levels in Harney County, OREPA zone 2
20.0%at or above 4 pCi/L
Median 0.7 pCi/L · 5 tests · 2.2 points below Washoe County
- Radon levels in Storey County, NVEPA zone 2
17.6%at or above 4 pCi/L
Median 2.3 pCi/L · 34 tests · 4.6 points below Washoe County
- Radon levels in Churchill County, NVEPA zone 2
12.4%at or above 4 pCi/L
Median 2.1 pCi/L · 161 tests · 9.8 points below Washoe County
- Radon levels in Placer County, CAEPA zone 2
7.4%at or above 4 pCi/L
Median 1.1 pCi/L · 283 tests · 14.8 points below Washoe County
- Radon levels in Lassen County, CAEPA zone 3
0.0%at or above 4 pCi/L
Median 1.1 pCi/L · 4 tests · 22.2 points below Washoe County
- Radon levels in Sierra County, CAEPA zone 2
0.0%at or above 4 pCi/L
Median 1.2 pCi/L · 1 test · 22.2 points below Washoe County
- Radon levels in Lake County, OREPA zone 2
0.0%at or above 4 pCi/L
Median 0.3 pCi/L · 4 tests · 22.2 points below Washoe County
View all 13 counties bordering Washoe County
- Radon levels in Modoc County, CAEPA zone 3
No CDC figure for 2008 to 2017; its page reads it against its own neighbours.
Washoe County, Cities and towns
Cities and towns in Washoe County
The Census Bureau estimates 509,386 residents in Washoe County for July 1, 2025, 21,658 more than in 2020 (+4.4%). That works out to 81 people per square mile of land. Reno alone is home to 283,621 of them, 55.7% of the total. Together its 2 incorporated places hold 77.6% of those residents; the other 22.4% live outside any of them. Testing is reported here more often than across the state: CDC's 5,046 reported tests for 2008 to 2017 come to 9.9 for every 1,000 residents (2025 estimate), against 3.3 for Nevada.
From Reno to Sparks, CDC publishes no figure by town: each reads Washoe County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Reno | 283,621 | +7.0% | 55.7% |
| Sparks | 111,902 | +2.8% | 22.0% |
Places in Washoe County with a city page: 1 of 1
2 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).
Washoe County, Homes
Homes in Washoe County
Of Washoe County's 213,392 homes, 59% are detached houses, against 60% across Nevada; 24% are in buildings of five or more homes. Half of its homes were built before 1990, close to Nevada's 1996: 9% date from before 1960 and 33% from 2000 or later. 59% 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 | Washoe County | Nevada |
|---|---|---|
| Housing units | 213,392 | 1,307,338 |
| Detached houses | 59% | 60% |
| In buildings of 5 or more | 24% | 22% |
| Mobile homes | 6% | 6% |
| Built before 1960 | 9% | 5% |
| Built since 2000 | 33% | 40% |
| Middle year built | 1990 | 1996 |
| Owner-occupied | 59% | 59% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.