Radon levels in Utah: Moderate
The model predicts a population-weighted basement average of 2.3 pCi/L (model estimate) across Utah's 29 counties - about 1.3× the US average of 1.8 pCi/L. Above-ground floors average 1.5 pCi/L.
Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.
7 / 29
EPA Zone 1 counties (24%)
22 / 0
Zone 2 / Zone 3 counties
0
counties predicted ≥ 4 pCi/L
1.3%
of ZIP codes predicted ≥ 4 pCi/L
Test Utah - the EPA says "consider fixing" in this range
The predicted basement average here is 2.3 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.
Monitor link goes to the Airthings store - use code RADONGRADE-10OFF at checkout for 10% off any Airthings monitor.
Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.
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What the data says about radon in Utah
According to the EPA zone map, 7 of Utah's 29 counties are EPA Zone 1 (24%), 22 are Zone 2 and 0 are Zone 3. Zone 2 (predicted screening average of 2-4 pCi/L) is the most common designation, with the 7 Zone 1 counties marking where the EPA expected the highest potential. Treat the map as a coarse prior: it predates two decades of test data and never replaces a test in your own home.
The 2001-2021 national model predicts a population-weighted basement average of 2.3 pCi/L for Utah (moderate range, 1.3× the US population-weighted average of 1.8). Of the 29 counties with predictions, 0 are predicted at or above 4 pCi/L, 25 in the 2-4 band and 4 below 2. The highest predicted county is Wasatch County at 3.9 pCi/L; the lowest is Davis County at 1.9 - a 1.9 pCi/L spread that means a statewide average tells you little about any one county.
89.3% of the state's modeled ZIP codes are predicted at or above 2 pCi/L, and 1.3% at or above the 4 pCi/L action level - below the national 4.2% at the action level but above the national 48.7% at 2 pCi/L. With more than half of ZIPs above 2, a test is worth doing before any purchase or renovation here.
Utah counties by predicted radon
Sorted highest to lowest predicted basement average (model estimate). 29 counties.
| County | Predicted basement | Upstairs | Grade | EPA zone | ZIPs |
|---|---|---|---|---|---|
| Wasatch County | 3.9 pCi/L | 2.7 | Moderate | EPA Zone 2 | 3 |
| Sevier County | 3.7 pCi/L | 2.4 | Moderate | EPA Zone 1 | 7 |
| Emery County | 3.4 pCi/L | 2.3 | Moderate | EPA Zone 2 | 3 |
| Daggett County | 3.2 pCi/L | 2.3 | Moderate | EPA Zone 2 | 2 |
| Piute County | 3.2 pCi/L | 2.2 | Moderate | EPA Zone 1 | 3 |
| Rich County | 3.2 pCi/L | 2.3 | Moderate | EPA Zone 2 | 4 |
| Juab County | 3.1 pCi/L | 2.1 | Moderate | EPA Zone 2 | 3 |
| Carbon County | 3.1 pCi/L | 2.3 | Moderate | EPA Zone 1 | 4 |
| Sanpete County | 3.1 pCi/L | 2.2 | Moderate | EPA Zone 1 | 10 |
| Duchesne County | 3.0 pCi/L | 2.0 | Moderate | EPA Zone 1 | 11 |
| Beaver County | 3.0 pCi/L | 2.3 | Moderate | EPA Zone 2 | 3 |
| Garfield County | 3.0 pCi/L | 2.2 | Moderate | EPA Zone 2 | 4 |
| Wayne County | 2.8 pCi/L | 1.9 | Moderate | EPA Zone 2 | 4 |
| San Juan County | 2.8 pCi/L | 1.7 | Moderate | EPA Zone 2 | 5 |
| Uintah County | 2.8 pCi/L | 2.3 | Moderate | EPA Zone 1 | 7 |
| Iron County | 2.8 pCi/L | 2.0 | Moderate | EPA Zone 2 | 9 |
| Cache County | 2.6 pCi/L | 1.8 | Moderate | EPA Zone 2 | 14 |
| Kane County | 2.6 pCi/L | 1.7 | Moderate | EPA Zone 2 | 5 |
| Box Elder County | 2.6 pCi/L | 1.8 | Moderate | EPA Zone 2 | 15 |
| Millard County | 2.6 pCi/L | 1.7 | Moderate | EPA Zone 2 | 4 |
| Utah County | 2.5 pCi/L | 1.5 | Moderate | EPA Zone 2 | 20 |
| Grand County | 2.4 pCi/L | 1.8 | Moderate | EPA Zone 1 | 2 |
| Morgan County | 2.4 pCi/L | 2.2 | Moderate | EPA Zone 2 | 1 |
| Salt Lake County | 2.2 pCi/L | 1.3 | Moderate | EPA Zone 2 | 35 |
| Summit County | 2.1 pCi/L | 1.9 | Moderate | EPA Zone 2 | 7 |
| Davis County | 1.9 pCi/L | 1.1 | Low | EPA Zone 2 | 10 |
| Tooele County | 1.9 pCi/L | 1.4 | Low | EPA Zone 2 | 7 |
| Washington County | 1.9 pCi/L | 1.3 | Low | EPA Zone 2 | 13 |
| Weber County | 1.9 pCi/L | 1.4 | Low | EPA Zone 2 | 9 |
Radon levels in Utah cities
The 22 most-populous Utah places among the 1,000 largest US cities (Census incorporated places and CDPs), by population. City figures are ZIP-land-weighted means of the model's ZIP predictions (model estimate).
| City | Population | Predicted basement | Upstairs | Grade | ZIPs ≥ 4 |
|---|---|---|---|---|---|
| Salt Lake City | 209,593 | 2.2 pCi/L | 1.5 | Moderate | 0% |
| West Valley City | 134,470 | 2.0 pCi/L | 1.0 | Moderate | 0% |
| West Jordan | 114,908 | 2.1 pCi/L | 1.2 | Moderate | 0% |
| Provo | 113,343 | 2.5 pCi/L | 1.7 | Moderate | 0% |
| St. George | 104,578 | 1.8 pCi/L | 1.2 | Low | 0% |
| Orem | 95,519 | 2.4 pCi/L | 1.1 | Moderate | 0% |
| Sandy | 91,943 | 2.5 pCi/L | 1.5 | Moderate | 0% |
| Lehi | 90,227 | 2.3 pCi/L | 1.6 | Moderate | 0% |
| Ogden | 87,267 | 1.9 pCi/L | 1.6 | Low | 0% |
| South Jordan | 84,528 | 2.6 pCi/L | 1.2 | Moderate | 0% |
| Layton | 83,516 | 1.9 pCi/L | 1.2 | Low | 0% |
| Millcreek | 62,205 | 2.0 pCi/L | 1.5 | Low | 0% |
| Herriman | 60,049 | 2.4 pCi/L | 1.6 | Moderate | 0% |
| Taylorsville | 57,098 | 2.3 pCi/L | 1.3 | Moderate | 0% |
| Eagle Mountain | 56,932 | 2.1 pCi/L | 1.5 | Moderate | 0% |
| Logan | 55,250 | 2.5 pCi/L | 1.8 | Moderate | 0% |
| Saratoga Springs | 52,532 | 2.1 pCi/L | 1.1 | Moderate | 0% |
| Draper | 49,602 | 2.2 pCi/L | 1.5 | Moderate | 0% |
| Murray | 49,553 | 2.1 pCi/L | 1.4 | Moderate | 0% |
| Spanish Fork | 45,557 | 2.3 pCi/L | 1.8 | Moderate | 0% |
| Riverton | 44,854 | 2.6 pCi/L | 1.6 | Moderate | 0% |
| Bountiful | 44,144 | 2.4 pCi/L | 1.6 | Moderate | 0% |
Highest-radon ZIP codes in Utah
The 10 Utah ZIP codes with the highest predicted basement average (model estimate), out of 224 modeled. A ZIP average is still an area figure - neighboring homes routinely test several pCi/L apart.
| ZIP | County | Predicted basement | Upstairs | Grade |
|---|---|---|---|---|
| 84754 | Sevier County | 5.1 pCi/L | 2.6 | High |
| 84032 | Wasatch County | 4.3 pCi/L | 2.6 | High |
| 84655 | Utah County | 4.2 pCi/L | 2.2 | High |
| 84739 | Sevier County | 3.7 pCi/L | 2.4 | Moderate |
| 84064 | Rich County | 3.5 pCi/L | 2.5 | Moderate |
| 84523 | Emery County | 3.5 pCi/L | 2.4 | Moderate |
| 84654 | Sevier County | 3.5 pCi/L | 2.5 | Moderate |
| 84526 | Carbon County | 3.5 pCi/L | 2.5 | Moderate |
| 84760 | Iron County | 3.4 pCi/L | 2.5 | Moderate |
| 84046 | Daggett County | 3.4 pCi/L | 2.3 | Moderate |
Utah radon questions
- Is radon high in Utah?
- Utah's population-weighted predicted basement average is 2.3 pCi/L, about 1.3× the US average of 1.8. 0 of its 29 modeled counties are predicted at or above the EPA action level of 4 pCi/L, 25 are in the 2-4 "consider fixing" range and 4 are below 2. 1.3% of Utah ZIP codes are predicted at 4 or higher.
- Which Utah county has the highest radon?
- Wasatch County has the highest predicted basement average in Utah at 3.9 pCi/L (EPA Zone 2). The lowest is Davis County at 1.9 pCi/L. These are area figures; individual homes in any county can test far higher.
- How many EPA Zone 1 counties are in Utah?
- 7 of Utah's 29 counties (24%) are EPA Zone 1 (highest potential), 22 are Zone 2 and 0 are Zone 3. The EPA zone map dates from 1993; the predicted values on this page come from a 2001-2021 model built on millions of actual tests, so the two can disagree for a given county.
- Should I test for radon in Utah?
- Yes - with some urgency. Utah's predicted average is in the moderate range, and 89.3% of its ZIP codes are predicted at 2 pCi/L or higher. A short-term charcoal kit or a continuous digital monitor will tell you your actual level within days.
Utah radon program
Utah's radon program page is at deq.utah.gov and, when we checked it, offered a low-cost test kit ordered online. The EPA also keeps a directory of every state radon contact: EPA state radon contacts page. Then read how to test and what mitigation costs.