Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
Locations and reports
Radon Levels in Kittitas County, Washington
EPA puts Kittitas County in Zone 2, its middle radon zone, and only 5 radon tests from it are on file with CDC (2020). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
12.5%
8.4 pts below WA
- Kittitas
- 12.5%
- Washington
- 20.9%
40 tests, 2019
Median result
0.3pCi/L
Below action level
- Kittitas
- 0.3 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2019
Tests reported
40
11th of 14 by tests
- Kittitas
- 40
- Spokane
- 952
Reported to CDC before any fix, 2019
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 Washington
10 of 14
Middle half
- Kittitas
- 12.5%
- Pend Oreille
- 51.4%
By share, of 14 with 30+ tests
Read a result for Kittitas County
Starts at Kittitas County's median, 0.3 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 0.3 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. Kittitas County's median reported result, 2019.
The data
Kittitas County, At a glance
Kittitas County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Kittitas County is a
USGS geologic potential: Moderate across 78% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Kittitas County, 2020
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 11.1% |
| 2015 | 50.0% |
| 2016 | 0.0% |
| 2017 | 33.3% |
| 2018 | 33.3% |
| 2019 | 12.5% |
| 2020 | 20.0% |
2020: 20.0%. Across these years the share ran from 0.0% to 50.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 5 tests were reported to CDC for Kittitas County over 2020, 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: 2020. Measured data period: 2005 to 2020 (every CDC figure on file).
Kittitas County, Compared
Kittitas County radon figures, compared
Calculated by Radon411Kittitas County reports fewer high tests than Washington overall. 12.5% of its 40 tests in 2019 were at or above 4 pCi/L. That is 8.4 points below the 20.9% pooled from 38 Washington counties.
The newest figure, in 2020, counts only 5 tests (20.0% at or above 4 pCi/L), too few to compare, so this reading uses the 40-test figure.
Ordered from highest share down, it comes 10th of 14 Washington counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 29.0%; Kittitas County sits 16.5 points below it.
Next door, the shares run from 2.4% in King County to 12.6% in Pierce County, with King County below Kittitas County. Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 12.5% share point the same way here.
Half the tests came in under 0.3 pCi/L and half over it; the single highest reached 8.2 pCi/L. The rest split 82.5% under 2 pCi/L and 5.0% from 2 to 4 (Washington: 66.1% and 13.1%).
The busiest year on file was 2019, with 40 tests reported; the quietest, 2018, had 3.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Kittitas County, Geology
The ground under Kittitas County
PredictedMost of the ground under Kittitas County is one class on USGS's geologic map: 77.5% of its land is moderate radon potential, with 22.5% low. The map puts 77.5% of Kittitas County in the area it calls Columbia Basin and 22.5% in Cascade Mountains. USGS gives the first a radon index of 10, in the moderate band (9 to 11), and the second 6, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Columbia Basin | Basaltic rocks low in uranium content. Uranium content of soils is moderately elevated. | Moderate | 10 | 77.5% |
| Cascade Mountains | Northern Cascade Mountains are Mesozoic metamorphic rocks intruded by Mesozoic and Tertiary granitic rocks. Southern Cascade Mountains are composed primarily of Tertiary and Holocene volcanic rocks. | Low | 6 | 22.5% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Kittitas County beside the ground around it
Across Washington 13.7% of the land is rated high; none of Kittitas County's is. Of the 6 counties that border it, 2 have more high-potential ground, Douglas County the most at 5.3%.
The map rates the ground, not the air in any home.
Local help
Kittitas County, Local resources
Radon testing and mitigation in Kittitas County
- Radon ProgramRadon Program, run by Washington State Department of Health, offers free or discounted test kits, and answers questions about testing and mitigation in Washington.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
We have a limited supply of free radon test kits.
- Compare kits
- See the Washington directoryNo professionals are listed in Washington yet. The state program can point you to registered testers and mitigators.
What Washington's program says
- Phone
- 360-236-3200
- doh.radon@doh.wa.gov
What it means
Kittitas County, Questions
Questions about radon in Kittitas County
Are radon levels high in Kittitas County?
In 2020, 20.0% of the radon tests reported to CDC for Kittitas County, Washington were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.0 pCi/L. Of 14 Washington counties with 30 or more tests for the same period, 9 reported a higher share; pooled, the state comes to 20.9%.
Which counties border Kittitas County?
Kittitas County borders 6 counties: Yakima County, Chelan County, Grant County, Douglas County, King County and Pierce County.
Products
Kittitas County, Products
Testing a home in Kittitas County
In Kittitas County, 12.5% of 40 tests reported to CDC in 2019 reached 4 pCi/L, against 20.9% pooled across Washington. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Kittitas County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
MonitorSafetySiren
Pro4 plug-in radon detector with a display and alarm
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
First reading: Within 48 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Kittitas County, Bordering counties
Counties bordering Kittitas County
Calculated by Radon411- Radon levels in Chelan CountyEPA zone 3
35.3%at or above 4 pCi/L
Median 1.8 pCi/L · 17 tests · 22.8 points above Kittitas County
- Radon levels in Grant CountyEPA zone 2
33.3%at or above 4 pCi/L
Median 1.8 pCi/L · 9 tests · 20.8 points above Kittitas County
- Radon levels in Pierce CountyEPA zone 3
12.6%at or above 4 pCi/L
Median 0.7 pCi/L · 848 tests · 0.1 points above Kittitas County
- Radon levels in Yakima CountyEPA zone 2
5.0%at or above 4 pCi/L
Median 1.1 pCi/L · 20 tests · 7.5 points below Kittitas County
- Radon levels in King CountyEPA zone 3
2.4%at or above 4 pCi/L
Median 0.3 pCi/L · 497 tests · 10.1 points below Kittitas County
- Radon levels in Douglas CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 2.2 pCi/L · 6 tests · 12.5 points below Kittitas County
Kittitas County, Cities and towns
Cities and towns in Kittitas County
The Census Bureau estimates 48,803 residents in Kittitas County for July 1, 2025, 1,980 more than in 2020 (+4.2%). That works out to 21 people per square mile of land. Its largest town, Ellensburg, has 21,308 residents, 43.7% of the total. Together its 5 incorporated places hold 54.5% of those residents; the other 45.5% live outside any of them. Testing is reported here more often than across the state: CDC's 40 reported tests for 2019 come to 0.8 for every 1,000 residents (2025 estimate), against 0.5 for Washington.
From Ellensburg to South Cle Elum, CDC publishes no figure by town: each reads Kittitas County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Ellensburg | 21,308 | −1.6% | 43.7% |
| Cle Elum | 2,288 | +5.2% | 4.7% |
| Kittitas | 1,440 | −0.9% | 3.0% |
| Roslyn | 962 | −0.1% | 2.0% |
| South Cle Elum | 588 | +4.3% | 1.2% |
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).
Kittitas County, Homes
Homes in Kittitas County
Of Kittitas County's 24,326 homes, 72% are detached houses, against 62% across Washington; 13% are in buildings of five or more homes. Half of its homes were built before 1991, close to Washington's 1984: 18% date from before 1960 and 35% from 2000 or later. 62% of occupied homes are lived in by their owner (Washington: 64%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Kittitas County | Washington |
|---|---|---|
| Housing units | 24,326 | 3,262,667 |
| Detached houses | 72% | 62% |
| In buildings of 5 or more | 13% | 22% |
| Mobile homes | 7% | 6% |
| Built before 1960 | 18% | 21% |
| Built since 2000 | 35% | 28% |
| Middle year built | 1991 | 1984 |
| Owner-occupied | 62% | 64% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.