Radon levels in Utah: Moderate
The model predicts a population-weighted basement average of 2.3 pCi/L 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
Utah counties by predicted radon
Sorted highest to lowest predicted basement average. 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 |
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 modeled area averages; 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
Many states offer free or discounted test kits and keep lists of certified mitigators. Find the Utah radon office through the EPA state radon contacts page. Then read how to test and what mitigation costs.