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
Locations and reports
Radon Levels in Jerome County, Idaho
EPA puts Jerome County in Zone 2, its middle radon zone, and 16.9% of its 65 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
16.9%
24.6 pts below ID
- Jerome
- 16.9%
- Idaho
- 41.5%
65 tests, 2008 to 2017
Median result
1.9pCi/L
Below action level
- Jerome
- 1.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
65
27th of 37 by tests
- Jerome
- 65
- Ada
- 3,030
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 Idaho
34 of 37
Lowest quarter
- Jerome
- 16.9%
- Bear Lake
- 78.1%
By share, of 37 with 30+ tests
Read a result for Jerome County
Starts at Jerome 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. Jerome County's median reported result, 2008 to 2017.
The data
Jerome County, At a glance
Jerome County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Jerome County is a
USGS geologic potential: Moderate across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Jerome County, 2008 to 2017, laboratory
Under 2 pCi/L: 51%2 to 4 pCi/L: 32%4 pCi/L and above: 17%
Of 65 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 33 | 50.8% |
| 2 to 4 pCi/L | 21 | 32.3% |
| 4 pCi/L and above | 11 | 16.9% |
What these figures count
These are the 65 tests reported to CDC for Jerome 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).
Jerome County, Compared
Jerome County radon figures, compared
Calculated by Radon411Jerome County's 65 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.9 pCi/L and a maximum of 8.1 pCi/L, and 16.9% reached 4 pCi/L. Idaho as a whole (44 Idaho counties, pooled) comes to 41.5%: 24.6 points higher than here.
Among its state's counties it ranks 34th 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, 33 tests (50.8%) came in under 2 pCi/L, against 31.5% statewide, and 21 tests (32.3%) fell between 2 and 4, against 26.9% statewide. CDC's ten-year totals for Jerome County went from 58 tests (2005 to 2014) to 65 (2008 to 2017), the share going from 15.5% to 16.9%.
EPA's 1993 zone map puts Jerome County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.
Next door, the shares run from 15.3% in Minidoka County to 59.5% in Cassia County, with Minidoka County below Jerome County.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Jerome County, Geology
The ground under Jerome County
PredictedUSGS's geologic map puts all of Jerome County's mapped land in one class: moderate radon potential. 98.8% of it lies in the area the map calls Eastern Snake river plain and Malheur-Boise-King Section, to which USGS gives a radon index of 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Eastern Snake river plain and Malheur-Boise-King Section | Basalt flows. | Moderate | 10 | 98.8% |
| Owyhee Upland | Tertiary and Quaternary basalt, andesite, and rhyolite. | Moderate | 9 | 1.2% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Jerome County beside the ground around it
Across Idaho 50.7% of the land is rated high; none of Jerome County's is. Of the 5 counties that border it, 2 have more high-potential ground, Gooding County the most at 53.8%.
The map rates the ground, not the air in any home.
Local help
Jerome County, Local resources
Radon testing and mitigation in Jerome 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
Jerome County, Questions
Questions about radon in Jerome County
Are radon levels high in Jerome County?
Over the 2008 to 2017 laboratory totals, 16.9% of the radon tests reported to CDC for Jerome County, Idaho were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.9 pCi/L. Of 37 Idaho counties with 30 or more tests for the same period, 33 reported a higher share; pooled, the state comes to 41.5%.
Which counties border Jerome County?
Jerome County borders 5 counties: Twin Falls County, Lincoln County, Gooding County, Cassia County and Minidoka County.
Products
Jerome County, Products
Testing a home in Jerome County
In Jerome County, 16.9% of 65 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 41.5% pooled across Idaho. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Jerome 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
Monitor
Wave Radon battery smart radon monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- App only
Method: Alpha spectrometry
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Jerome County, Bordering counties
Counties bordering Jerome County
Calculated by Radon411- Radon levels in Cassia CountyEPA zone 2
59.5%at or above 4 pCi/L
Median 5.4 pCi/L · 121 tests · 42.6 points above Jerome County
- Radon levels in Lincoln CountyEPA zone 2
40.0%at or above 4 pCi/L
Median 3.3 pCi/L · 20 tests · 23.1 points above Jerome County
- Radon levels in Gooding CountyEPA zone 1
28.4%at or above 4 pCi/L
Median 2.4 pCi/L · 67 tests · 11.5 points above Jerome County
- Radon levels in Twin Falls CountyEPA zone 2
24.1%at or above 4 pCi/L
Median 2.4 pCi/L · 369 tests · 7.2 points above Jerome County
- Radon levels in Minidoka CountyEPA zone 2
15.3%at or above 4 pCi/L
Median 1.8 pCi/L · 72 tests · 1.6 points below Jerome County
Jerome County, Cities and towns
Cities and towns in Jerome County
Jerome County is growing: the Census Bureau puts it at 26,362 residents on July 1, 2025, up 8.6% from 24,269 in 2020. That works out to 44 people per square mile of land. Jerome alone is home to 13,731 of them, 52.1% of the total. Together its 3 incorporated places hold 56.8% of those residents; the other 43.2% live outside any of them. Reported testing is thin here: 65 tests over 2008 to 2017, or 2.5 for every 1,000 residents (2025 estimate), where Idaho as a whole comes to 6.4.
From Jerome to Eden, CDC publishes no figure by town: each reads Jerome County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Jerome | 13,731 | +11.0% | 52.1% |
| Hazelton | 827 | +2.5% | 3.1% |
| Eden | 406 | +3.0% | 1.5% |
3 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).
Jerome County, Homes
Homes in Jerome County
Jerome County is a place of houses on their own lots: 82% of its 8,725 homes are detached single-family houses, against 74% across Idaho. Half of its homes were built before 1983, close to Idaho's 1990: 23% date from before 1960 and 30% from 2000 or later. Owners live in 75% of the occupied homes (Idaho: 72%), so for most households a test and a fix are their own to order.
| Homes | Jerome County | Idaho |
|---|---|---|
| Housing units | 8,725 | 776,683 |
| Detached houses | 82% | 74% |
| In buildings of 5 or more | 2% | 9% |
| Mobile homes | 10% | 7% |
| Built before 1960 | 23% | 18% |
| Built since 2000 | 30% | 35% |
| Middle year built | 1983 | 1990 |
| Owner-occupied | 75% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.