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Radon Levels in Cache County, Utah

EPA puts Cache County in Zone 2, its middle radon zone, and high results are common there: 53.8% of the 994 radon tests reported to CDC (2023) came back 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    53.8%

    17.7 pts above UT

    Cache
    53.8%
    Utah
    36.1%

    994 tests, 2023

  • Median result

    4.4pCi/L

    Action level reached

    Cache
    4.4 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    994

    5th of 22 by tests

    Cache
    994
    Salt Lake
    9,658

    Reported to CDC before any fix, 2023

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Utah

    8 of 22

    Middle half

    Cache
    53.8%
    Beaver
    66.7%

    By share, of 22 with 30+ tests

Read a result for Cache County

Starts at Cache County's median, 4.4 pCi/L

4.4pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 4.4 pCi/L

At or above 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Cache County's median reported result, 2023.

Interpret this readingWhat a fix costs

The data

Cache County, At a glance

Cache County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Cache County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 55% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Cache County, 2023

Share of reported tests at or above 4 pCi/L, by year, Cache County
Share of reported tests at or above 4 pCi/L, by year, Cache County
YearShare of reported tests at or above 4 pCi/L
201456.9%
201555.9%
201662.9%
201751.0%
201837.9%
201955.7%
202048.6%
202150.0%
202252.7%
202353.8%

2023: 53.8%. Across these years the share ran from 37.9% to 62.9%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 994 tests reported to CDC for Cache County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Cache County, Compared

Cache County radon figures, compared

Calculated by Radon411

More than half: 53.8% of the 994 radon tests reported to CDC for Cache County in 2023 read at least 4 pCi/L. That places it 8th of 22 Utah counties with 30 or more tests for the same period. That is 17.7 points above the 36.1% pooled from 29 Utah counties.

The median result, 4.4 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 133.9 pCi/L. The rest split 20.3% under 2 pCi/L and 25.9% from 2 to 4 (Utah: 35.4% and 28.5%). The reported tests do not follow EPA's Zone 2 label for Cache County (predicted average between 2 and 4 pCi/L): 53.8% of them reached 4 pCi/L, fewer than that label suggests.

1 of its 2 bordering counties with figures ran higher, led by Box Elder County at 57.9%; Weber County reported 28.6%. Statewide for the same period, Beaver County reported the highest share (66.7%) and Washington County the lowest (9.9%).

The busiest year on file was 2022, with 1,365 tests reported; the quietest, 2021, had 174.

Over 10 years of annual figures the share fell 3.1 points, from 56.9% in 2014 to 53.8% in 2023; its peak was 62.9% in 2016. Nationally, every county with a figure for the same period pools to 33.4%; Cache County sits 20.4 points above it. CDC also counts 154 tests taken after mitigation in Cache County for the same period: tests in homes where a fix was already in.

Share of reported tests at or above 4 pCi/L by year, Cache County against Utah2014 to 2023, years with 30 or more tests: Cache County 56.9% to 53.8%, the state's pooled share 36.1% in 2023.
Cache CountyUtah, pooled
Share of reported tests at or above 4 pCi/L by year, Cache County against Utah: data table
YearTestsCache County, at or above 4 pCi/LUtah, pooled
201440456.9%43.4%
201551555.9%42.3%
201644762.9%39.8%
201725951.0%38.2%
201837737.9%36.6%
201917455.7%37.7%
202022248.6%37.6%
202117450.0%34.2%
20221,36552.7%37.7%
202399453.8%36.1%
Cache County against Utah, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Cache County
Cache County99453.8%4.4 pCi/LThis county
Utah, pooled29 counties, pooled27,42236.1%Not pooled−17.7 points
United States, pooled642 counties, pooled128,74033.4%Not pooled−20.4 points
Beaver Countyhighest in the state4266.7%9.3 pCi/L+12.9 points
Washington Countylowest in the state6579.9%1.3 pCi/L−43.9 points
Box Elder County, UTborders it44957.9%4.9 pCi/L+4.1 points
Rich County, UTborders it1353.8%4.8 pCi/LLevel
Weber County, UTborders it1,66928.6%2.1 pCi/L−25.2 points
Where Cache County's reported results fell, 2023, beside Utah and the United States
ResultCache County testsCache County shareUtah shareU.S. shareAgainst Utah
Under 2 pCi/L20220.3%35.4%41.4%−15.1 points
2 to 4 pCi/L25725.9%28.5%25.2%−2.6 points
4 pCi/L and above53553.8%36.1%33.4%+17.7 points
Cache County ranked among the 22 Utah counties with 30 or more tests, by share at or above 4 pCi/L, 2023
CountyRankTestsAt or above 4 pCi/LMedian
Sanpete County3 of 2215060.0%4.6 pCi/L
Morgan County4 of 2220759.4%5.0 pCi/L
Millard County5 of 225558.2%4.4 pCi/L
Box Elder County6 of 2244957.9%4.9 pCi/L
Sevier County7 of 2210157.4%4.9 pCi/L
Cache County8 of 2299453.8%4.4 pCi/L
Wasatch County9 of 2232451.9%4.2 pCi/L
Uintah County10 of 2210451.0%4.2 pCi/L
Tooele County11 of 2257351.0%4.1 pCi/L
Utah County12 of 227,83340.6%3.2 pCi/L
Duchesne County13 of 228139.5%3.2 pCi/L
Cache County radon tests by year, against Utah's pooled share
YearTestsAt or above 4 pCi/LMedianHighestUtah, pooledChange from the row before
202399453.8%4.4 pCi/L133.9 pCi/L36.1%+1.1 points
20221,36552.7%4.2 pCi/L79.1 pCi/L37.7%+2.7 points
202117450.0%4.0 pCi/L54.7 pCi/L34.2%+1.4 points
202022248.6%3.9 pCi/L80.8 pCi/L37.6%−7.1 points
201917455.7%4.7 pCi/L86.2 pCi/L37.7%+17.8 points
201837737.9%2.7 pCi/L67.5 pCi/L36.6%−13.1 points
201725951.0%4.2 pCi/L48.9 pCi/L38.2%−11.9 points
201644762.9%5.3 pCi/L99.3 pCi/L39.8%+7.0 points
201551555.9%4.7 pCi/L89.0 pCi/L42.3%−1.0 points
201440456.9%4.7 pCi/L96.2 pCi/L43.4%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Cache County, Geology

The ground under Cache County

Predicted

USGS's geologic map splits Cache County: 55.3% of its land is moderate radon potential and 44.7% high. The map puts 55.3% of Cache County in the area it calls Basin and Range and 41.0% in Wasatch Range, with one smaller area beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 14, in the high band (12 to 17).

USGS's geologic areas under Cache County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Basin and RangeCenozoic to Paleozoic sedimentary rocks.Moderate1155.3%
Wasatch RangePrecambrian granite and gneiss and Tertiary igneous rocks that have relatively low uranium concentrations.High1441.0%
Northern Rocky MountainsTertiary sandstone, mudstone, limestone.High133.7%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Cache County beside the ground around it

Cache County has more high-potential ground than Utah as a whole: 44.7% of its land against 32.8%. Of the 6 counties that border it, 1 has more high-potential ground, Rich County the most at 66.7%.

Share of land by USGS radon potential: Cache County, the 6 counties bordering it and Utah
AreaEPA zoneLow potentialModerate potentialHigh potential
Cache CountyZone 2None55.3%44.7%
Rich CountyZone 2None33.3%66.7%
Weber CountyZone 2None56.7%43.3%
Franklin County, IDZone 2None68.4%31.6%
Bear Lake County, IDZone 2None96.7%3.3%
Oneida County, IDZone 2None99.6%0.4%
Box Elder CountyZone 2None97.4%2.6%
Utah29 counties, pooled by land areaVariesNone67.2%32.8%

The map rates the ground, not the air in any home.

Local help

Cache County, Local resources

Radon testing and mitigation in Cache County

What Utah's program says
Phone
(801) 536-0091
Disclosure when a home is sold or rented
Utah requires that sellers disclose "Hazardous Conditions: Are there any hazardous conditions on the Property such as Radon gas in house or well?"

What it means

Cache County, Questions

Questions about radon in Cache County

Are radon levels high in Cache County?

In 2023, 53.8% of the radon tests reported to CDC for Cache County, Utah were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.4 pCi/L. Of 22 Utah counties with 30 or more tests for the same period, 7 reported a higher share; pooled, the state comes to 36.1%.

Which counties border Cache County?

Cache County borders 6 counties: Rich County, UT, Weber County, UT, Franklin County, ID, Bear Lake County, ID, Oneida County, ID and Box Elder County, UT.

Products

Cache County, Products

Testing a home in Cache County

In Cache County, 53.8% of 994 tests reported to CDC in 2023 reached 4 pCi/L, against 36.1% pooled across Utah. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Cache County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Cache County homes, compared

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Cache County, Bordering counties

Counties bordering Cache County

Calculated by Radon411

Cache County, Cities and towns

Cities and towns in Cache County

Cache County is growing: the Census Bureau puts it at 145,000 residents on July 1, 2025, up 8.5% from 133,636 in 2020. That works out to 124 people per square mile of land. Its largest town, Logan, has 55,576 residents, 38.3% of the total. Together its 19 incorporated places hold 94.6% of those residents; the other 5.4% live outside any of them. CDC's 994 reported tests for 2023 work out to 6.9 per 1,000 residents (2025 estimate), close to Utah's 7.7.

From Logan to Cornish, CDC publishes no figure by town: each reads Cache County's.

The 12 largest cities and towns in Cache County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Logan55,576+5.1%38.3%
Smithfield15,153+10.8%10.5%
North Logan11,608+5.6%8.0%
Hyrum11,132+17.9%7.7%
Providence9,539+14.9%6.6%
Nibley8,975+22.3%6.2%
Hyde Park5,786+10.1%4.0%
Wellsville4,303+5.7%3.0%
Richmond3,130+6.3%2.2%
Millville2,508+8.1%1.7%
River Heights2,253+4.2%1.6%
Lewiston1,940+0.4%1.3%
  • Mendon
  • Paradise
  • Newton
  • Clarkston
  • Trenton
  • Amalga
  • Cornish

19 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).

Cache County, Homes

Homes in Cache County

Of Cache County's 45,454 homes, 64% are detached houses, against 67% across Utah; 13% are in buildings of five or more homes. Half of its homes were built before 1991, close to Utah's 1991: 18% date from before 1960 and 36% from 2000 or later. 64% of occupied homes are lived in by their owner (Utah: 71%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Cache County, Utah, 2019 to 2023
HomesCache CountyUtah
Housing units45,4541,193,082
Detached houses64%67%
In buildings of 5 or more13%16%
Mobile homes2%3%
Built before 196018%16%
Built since 200036%37%
Middle year built19911991
Owner-occupied64%71%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.