Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Latah County, Idaho
EPA puts Latah County in Zone 1, its highest radon zone, and 26.0% of its 150 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
26.0%
15.5 pts below ID
- Latah
- 26.0%
- Idaho
- 41.5%
150 tests, 2008 to 2017
Median result
1.7pCi/L
Below action level
- Latah
- 1.7 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
150
14th of 37 by tests
- Latah
- 150
- Ada
- 3,030
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Idaho
25 of 37
Middle half
- Latah
- 26.0%
- Bear Lake
- 78.1%
By share, of 37 with 30+ tests
Read a result for Latah County
Starts at Latah County's median, 1.7 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.7 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. Latah County's median reported result, 2008 to 2017.
The data
Latah County, At a glance
Latah County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Latah County in
USGS geologic potential: High across 57% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Latah County, 2008 to 2017, laboratory
Under 2 pCi/L: 54%2 to 4 pCi/L: 20%4 pCi/L and above: 26%
Of 150 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 81 | 54.0% |
| 2 to 4 pCi/L | 30 | 20.0% |
| 4 pCi/L and above | 39 | 26.0% |
What these figures count
These are the 150 tests reported to CDC for Latah 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).
Latah County, Compared
Latah County radon figures, compared
Calculated by Radon411Latah County's 150 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.7 pCi/L and a maximum of 24.0 pCi/L, and 26.0% reached 4 pCi/L. Idaho as a whole (44 Idaho counties, pooled) comes to 41.5%: 15.5 points higher than here.
Among its state's counties it ranks 25th of 37 Idaho counties with 30 or more tests for the same period. Statewide for the same period, Bear Lake County reported the highest share (78.1%) and Payette County the lowest (4.9%).
Below the action level, 81 tests (54.0%) came in under 2 pCi/L, against 31.5% statewide, and 30 tests (20.0%) fell between 2 and 4, against 26.9% statewide. CDC's ten-year totals for Latah County went from 118 tests (2005 to 2014) to 150 (2008 to 2017), the share going from 28.0% to 26.0%.
EPA's 1993 zone map puts Latah County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 57% of the county's land high radon potential.
Next door, the shares run from 22.1% in Nez Perce County to 63.0% in Shoshone County, with Whitman County, WA and Nez Perce County below Latah County.
CDC also counts 11 tests taken after mitigation in Latah County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Latah County, Geology
The ground under Latah County
PredictedUSGS's geologic map splits Latah County: 56.9% of its land is high radon potential and 12.1% moderate and 31.0% low. The map puts 56.9% of Latah County in the area it calls Northern Rocky Mountain Province and 31.0% in Seven Devils and Tri-State Uplands, with one smaller area beside them. USGS gives the first a radon index of 12, in the high band (12 to 17), and the second 8, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Northern Rocky Mountain Province | Diorite and granite of the Idaho batholith. | High | 12 | 56.9% |
| Seven Devils and Tri-State Uplands | Columbia River basalt flows. | Low | 8 | 31.0% |
| Palouse Hills | Basalt, locally covered by loess. | Moderate | 10 | 12.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Latah County beside the ground around it
On high-potential ground Latah County is close to Idaho as a whole: 56.9% of its land against 50.7%. Of the 5 counties that border it, 3 have more high-potential ground, Shoshone County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Latah County, Local resources
Radon testing and mitigation in Latah County
- DHW Environmental Health ProgramDHW Environmental Health Program, run by Idaho Department of Health and Welfare, offers free or discounted test kits, and answers questions about testing and mitigation in Idaho.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Order a free radon test kit.
- Compare kits
- See the Idaho directoryNo professionals are listed in Idaho yet. The state program can point you to registered testers and mitigators.
What Idaho's program says
- Phone
- 800-445-8647
- radon@dhw.idaho.gov
What it means
Latah County, Questions
Questions about radon in Latah County
Are radon levels high in Latah County?
Over the 2008 to 2017 laboratory totals, 26.0% of the radon tests reported to CDC for Latah County, Idaho were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.7 pCi/L. Of 37 Idaho counties with 30 or more tests for the same period, 24 reported a higher share; pooled, the state comes to 41.5%.
Which counties border Latah County?
Latah County borders 5 counties: Benewah County, ID, Nez Perce County, ID, Whitman County, WA, Clearwater County, ID and Shoshone County, ID.
Products
Latah County, Products
Testing a home in Latah County
In Latah County, 26.0% of 150 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 41.5% pooled across Idaho. In Zone 1 the year-round level in Latah County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
MonitorX-Sense
XR0B-SR battery digital radon monitor with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Latah County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Latah County
Explore
Latah County, Bordering counties
Counties bordering Latah County
Calculated by Radon411- Radon levels in Shoshone County, IDEPA zone 1
63.0%at or above 4 pCi/L
Median 5.7 pCi/L · 81 tests · 37.0 points above Latah County
- Radon levels in Benewah County, IDEPA zone 1
31.0%at or above 4 pCi/L
Median 2.4 pCi/L · 29 tests · 5.0 points above Latah County
- Radon levels in Clearwater County, IDEPA zone 1
30.3%at or above 4 pCi/L
Median 1.8 pCi/L · 33 tests · 4.3 points above Latah County
- Radon levels in Whitman County, WAEPA zone 2
22.4%at or above 4 pCi/L
Median 1.5 pCi/L · 58 tests · 3.6 points below Latah County
- Radon levels in Nez Perce County, IDEPA zone 3
22.1%at or above 4 pCi/L
Median 2.3 pCi/L · 149 tests · 3.9 points below Latah County
Latah County, Cities and towns
Cities and towns in Latah County
Latah County is growing: the Census Bureau puts it at 41,842 residents on July 1, 2025, up 5.6% from 39,633 in 2020. That works out to 39 people per square mile of land. Moscow alone is home to 26,721 of them, 63.9% of the total. Together its 9 incorporated places hold 75.1% of those residents; the other 24.9% live outside any of them. Reported testing is thin here: 150 tests over 2008 to 2017, or 3.6 for every 1,000 residents (2025 estimate), where Idaho as a whole comes to 6.4.
From Moscow to Bovill, CDC publishes no figure by town: each reads Latah County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Moscow | 26,721 | +4.7% | 63.9% |
| Genesee | 1,094 | +6.0% | 2.6% |
| Troy | 925 | +5.1% | 2.2% |
| Potlatch | 797 | +4.0% | 1.9% |
| Juliaetta | 644 | +3.0% | 1.5% |
| Deary | 531 | +4.9% | 1.3% |
| Kendrick | 300 | +3.4% | 0.7% |
| Onaway | 218 | +10.7% | 0.5% |
| Bovill | 195 | +3.2% | 0.5% |
9 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).
Latah County, Homes
Homes in Latah County
Of Latah County's 17,429 homes, 56% are detached houses, against 74% across Idaho; 21% are in buildings of five or more homes. The homes are older than Idaho's as a whole: half were built before 1978 (1990 for Idaho), and 25% date from before 1960. 61% of occupied homes are lived in by their owner (Idaho: 72%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Latah County | Idaho |
|---|---|---|
| Housing units | 17,429 | 776,683 |
| Detached houses | 56% | 74% |
| In buildings of 5 or more | 21% | 9% |
| Mobile homes | 11% | 7% |
| Built before 1960 | 25% | 18% |
| Built since 2000 | 23% | 35% |
| Middle year built | 1978 | 1990 |
| Owner-occupied | 61% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.