Radon levels in Kentucky: Moderate
The model predicts a population-weighted basement average of 2.5 pCi/L (model estimate) across Kentucky's 120 counties - about 1.4× 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.
30 / 120
EPA Zone 1 counties (25%)
82 / 8
Zone 2 / Zone 3 counties
0
counties predicted ≥ 4 pCi/L
0.6%
of ZIP codes predicted ≥ 4 pCi/L
Test Kentucky - the EPA says "consider fixing" in this range
The predicted basement average here is 2.5 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.
Affiliate links: we may earn a commission from Airthings or Amazon at no extra cost to you.
What the data says about radon in Kentucky
On the EPA's 1993 radon zone map, 30 of Kentucky's 120 counties are EPA Zone 1 (25%), 82 are Zone 2 and 8 are Zone 3. Zone 2 (predicted screening average of 2-4 pCi/L) is the most common designation, with the 30 Zone 1 counties marking where the EPA expected the highest potential. That classification has not been revised since 1993; it describes counties, not homes, and elevated readings turn up in Zone 3 counties every year.
Kentucky models out at 2.5 pCi/L predicted basement average (moderate; 1.4× the US population-weighted average of 1.8). Of the 120 counties with predictions, 0 are predicted at or above 4 pCi/L, 100 in the 2-4 band and 20 below 2. The highest predicted county is Jessamine County at 3.7 pCi/L; the lowest is McCracken County at 1.5 - a 2.2 pCi/L spread that means a statewide average tells you little about any one county.
At ZIP-code resolution, 0.6% of Kentucky ZIPs are predicted at 4 pCi/L or higher in the basement and 71.8% at 2 or higher - 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.
Kentucky counties by predicted radon
Sorted highest to lowest predicted basement average (model estimate). 120 counties.
| County | Predicted basement | Upstairs | Grade | EPA zone | ZIPs |
|---|---|---|---|---|---|
| Jessamine County | 3.7 pCi/L | 2.0 | Moderate | EPA Zone 1 | 2 |
| Woodford County | 3.7 pCi/L | 2.3 | Moderate | EPA Zone 1 | 2 |
| Franklin County | 3.5 pCi/L | 2.3 | Moderate | EPA Zone 1 | 1 |
| Scott County | 3.5 pCi/L | 2.6 | Moderate | EPA Zone 1 | 3 |
| Bourbon County | 3.4 pCi/L | 2.2 | Moderate | EPA Zone 1 | 1 |
| Nelson County | 3.3 pCi/L | 1.8 | Moderate | EPA Zone 1 | 7 |
| Fayette County | 3.3 pCi/L | 2.2 | Moderate | EPA Zone 1 | 14 |
| Mercer County | 3.3 pCi/L | 2.1 | Moderate | EPA Zone 1 | 2 |
| Marion County | 3.2 pCi/L | 2.1 | Moderate | EPA Zone 1 | 6 |
| Boyle County | 3.2 pCi/L | 2.0 | Moderate | EPA Zone 1 | 4 |
| Harrison County | 3.2 pCi/L | 1.9 | Moderate | EPA Zone 1 | 2 |
| Bullitt County | 3.1 pCi/L | 1.9 | Moderate | EPA Zone 1 | 5 |
| Estill County | 3.1 pCi/L | 2.2 | Moderate | EPA Zone 2 | 2 |
| Taylor County | 3.1 pCi/L | 1.9 | Moderate | EPA Zone 1 | 2 |
| Pulaski County | 3.0 pCi/L | 1.6 | Moderate | EPA Zone 1 | 7 |
| Hart County | 2.9 pCi/L | 1.8 | Moderate | EPA Zone 1 | 8 |
| Casey County | 2.9 pCi/L | 1.6 | Moderate | EPA Zone 1 | 7 |
| Cumberland County | 2.8 pCi/L | 1.8 | Moderate | EPA Zone 1 | 1 |
| Lincoln County | 2.8 pCi/L | 1.5 | Moderate | EPA Zone 1 | 4 |
| Russell County | 2.8 pCi/L | 1.6 | Moderate | EPA Zone 1 | 2 |
| Warren County | 2.8 pCi/L | 3.2 | Moderate | EPA Zone 1 | 8 |
| Green County | 2.8 pCi/L | 1.8 | Moderate | EPA Zone 1 | 3 |
| Metcalfe County | 2.8 pCi/L | 1.6 | Moderate | EPA Zone 1 | 5 |
| Monroe County | 2.8 pCi/L | 1.7 | Moderate | EPA Zone 1 | 5 |
| Montgomery County | 2.8 pCi/L | 1.4 | Moderate | EPA Zone 2 | 2 |
| Barren County | 2.7 pCi/L | 1.8 | Moderate | EPA Zone 1 | 4 |
| Powell County | 2.7 pCi/L | 1.6 | Moderate | EPA Zone 2 | 3 |
| Adair County | 2.7 pCi/L | 1.7 | Moderate | EPA Zone 1 | 4 |
| Anderson County | 2.7 pCi/L | 1.6 | Moderate | EPA Zone 2 | 1 |
| Wayne County | 2.7 pCi/L | 1.4 | Moderate | EPA Zone 2 | 3 |
| Fleming County | 2.7 pCi/L | 1.5 | Moderate | EPA Zone 2 | 4 |
| Pendleton County | 2.6 pCi/L | 1.7 | Moderate | EPA Zone 1 | 3 |
| Garrard County | 2.6 pCi/L | 1.7 | Moderate | EPA Zone 2 | 2 |
| Rockcastle County | 2.6 pCi/L | 1.5 | Moderate | EPA Zone 2 | 4 |
| Madison County | 2.6 pCi/L | 1.4 | Moderate | EPA Zone 2 | 3 |
| Bath County | 2.5 pCi/L | 1.4 | Moderate | EPA Zone 2 | 4 |
| Clay County | 2.5 pCi/L | 1.3 | Moderate | EPA Zone 2 | 3 |
| Nicholas County | 2.5 pCi/L | 1.5 | Moderate | EPA Zone 2 | 2 |
| Logan County | 2.5 pCi/L | 1.6 | Moderate | EPA Zone 2 | 5 |
| Shelby County | 2.5 pCi/L | 1.6 | Moderate | EPA Zone 2 | 5 |
| Laurel County | 2.5 pCi/L | 1.1 | Moderate | EPA Zone 2 | 5 |
| Owsley County | 2.5 pCi/L | 1.3 | Moderate | EPA Zone 2 | 2 |
| Meade County | 2.4 pCi/L | 1.8 | Moderate | EPA Zone 2 | 8 |
| Oldham County | 2.4 pCi/L | 1.8 | Moderate | EPA Zone 2 | 7 |
| Washington County | 2.4 pCi/L | 1.4 | Moderate | EPA Zone 2 | 3 |
| Allen County | 2.4 pCi/L | 1.6 | Moderate | EPA Zone 1 | 3 |
| Breathitt County | 2.4 pCi/L | 1.5 | Moderate | EPA Zone 2 | 5 |
| Whitley County | 2.4 pCi/L | 1.2 | Moderate | EPA Zone 2 | 4 |
| Robertson County | 2.4 pCi/L | 1.4 | Moderate | EPA Zone 1 | 1 |
| Simpson County | 2.4 pCi/L | 1.6 | Moderate | EPA Zone 2 | 1 |
| Grant County | 2.4 pCi/L | 1.4 | Moderate | EPA Zone 2 | 5 |
| Henry County | 2.4 pCi/L | 1.6 | Moderate | EPA Zone 2 | 9 |
| Rowan County | 2.4 pCi/L | 1.3 | Moderate | EPA Zone 2 | 2 |
| Clinton County | 2.4 pCi/L | 1.3 | Moderate | EPA Zone 2 | 1 |
| Morgan County | 2.4 pCi/L | 1.2 | Moderate | EPA Zone 2 | 5 |
| Lee County | 2.4 pCi/L | 1.2 | Moderate | EPA Zone 2 | 2 |
| Carter County | 2.4 pCi/L | 1.3 | Moderate | EPA Zone 2 | 4 |
| Christian County | 2.4 pCi/L | 1.8 | Moderate | EPA Zone 2 | 8 |
| Hardin County | 2.4 pCi/L | 1.5 | Moderate | EPA Zone 2 | 10 |
| Boone County | 2.4 pCi/L | 1.3 | Moderate | EPA Zone 2 | 7 |
| Elliott County | 2.4 pCi/L | 1.1 | Moderate | EPA Zone 2 | 2 |
| Jefferson County | 2.3 pCi/L | 1.5 | Moderate | EPA Zone 1 | 34 |
| Letcher County | 2.3 pCi/L | 1.1 | Moderate | EPA Zone 2 | 20 |
| Bell County | 2.3 pCi/L | 1.0 | Moderate | EPA Zone 2 | 11 |
| Mason County | 2.3 pCi/L | 1.4 | Moderate | EPA Zone 2 | 4 |
| Menifee County | 2.3 pCi/L | 1.1 | Moderate | EPA Zone 2 | 4 |
| Jackson County | 2.3 pCi/L | 1.1 | Moderate | EPA Zone 2 | 4 |
| Larue County | 2.3 pCi/L | 1.6 | Moderate | EPA Zone 2 | 2 |
| Lewis County | 2.3 pCi/L | 1.3 | Moderate | EPA Zone 2 | 5 |
| Magoffin County | 2.3 pCi/L | 1.1 | Moderate | EPA Zone 2 | 3 |
| Knox County | 2.3 pCi/L | 1.1 | Moderate | EPA Zone 2 | 15 |
| Trimble County | 2.3 pCi/L | 1.4 | Moderate | EPA Zone 2 | 3 |
| Lawrence County | 2.3 pCi/L | 1.2 | Moderate | EPA Zone 2 | 6 |
| McCreary County | 2.3 pCi/L | 1.0 | Moderate | EPA Zone 2 | 5 |
| Pike County | 2.3 pCi/L | 1.1 | Moderate | EPA Zone 2 | 35 |
| Owen County | 2.3 pCi/L | 1.4 | Moderate | EPA Zone 2 | 3 |
| Floyd County | 2.3 pCi/L | 1.2 | Moderate | EPA Zone 2 | 28 |
| Harlan County | 2.3 pCi/L | 1.1 | Moderate | EPA Zone 2 | 21 |
| Grayson County | 2.2 pCi/L | 1.3 | Moderate | EPA Zone 2 | 4 |
| Knott County | 2.2 pCi/L | 1.1 | Moderate | EPA Zone 2 | 21 |
| Wolfe County | 2.2 pCi/L | 1.1 | Moderate | EPA Zone 2 | 3 |
| Clark County | 2.2 pCi/L | 1.3 | Moderate | EPA Zone 1 | 1 |
| Bracken County | 2.2 pCi/L | 1.4 | Moderate | EPA Zone 2 | 3 |
| Greenup County | 2.2 pCi/L | 1.3 | Moderate | EPA Zone 2 | 7 |
| Breckinridge County | 2.2 pCi/L | 1.4 | Moderate | EPA Zone 2 | 13 |
| Perry County | 2.2 pCi/L | 1.1 | Moderate | EPA Zone 2 | 17 |
| Johnson County | 2.1 pCi/L | 1.1 | Moderate | EPA Zone 2 | 16 |
| Leslie County | 2.1 pCi/L | 1.0 | Moderate | EPA Zone 2 | 15 |
| Spencer County | 2.1 pCi/L | 1.5 | Moderate | EPA Zone 2 | 2 |
| Martin County | 2.1 pCi/L | 1.1 | Moderate | EPA Zone 2 | 7 |
| Caldwell County | 2.1 pCi/L | 1.5 | Moderate | EPA Zone 2 | 2 |
| Ohio County | 2.1 pCi/L | 1.1 | Moderate | EPA Zone 2 | 11 |
| Boyd County | 2.1 pCi/L | 1.4 | Moderate | EPA Zone 2 | 4 |
| Lyon County | 2.1 pCi/L | 1.5 | Moderate | EPA Zone 2 | 2 |
| Butler County | 2.1 pCi/L | 1.1 | Moderate | EPA Zone 2 | 3 |
| Carroll County | 2.1 pCi/L | 1.4 | Moderate | EPA Zone 2 | 3 |
| Crittenden County | 2.0 pCi/L | 1.1 | Moderate | EPA Zone 2 | 1 |
| Edmonson County | 2.0 pCi/L | 1.2 | Moderate | EPA Zone 2 | 5 |
| Trigg County | 2.0 pCi/L | 1.4 | Moderate | EPA Zone 2 | 1 |
| Hancock County | 2.0 pCi/L | 1.1 | Moderate | EPA Zone 2 | 3 |
| Gallatin County | 2.0 pCi/L | 1.3 | Low | EPA Zone 2 | 2 |
| Muhlenberg County | 2.0 pCi/L | 1.1 | Low | EPA Zone 2 | 11 |
| Webster County | 1.9 pCi/L | 1.1 | Low | EPA Zone 2 | 5 |
| Henderson County | 1.9 pCi/L | 1.1 | Low | EPA Zone 2 | 5 |
| Kenton County | 1.9 pCi/L | 1.3 | Low | EPA Zone 2 | 8 |
| Union County | 1.9 pCi/L | 1.0 | Low | EPA Zone 2 | 4 |
| Hopkins County | 1.9 pCi/L | 1.1 | Low | EPA Zone 2 | 9 |
| McLean County | 1.9 pCi/L | 1.0 | Low | EPA Zone 2 | 5 |
| Daviess County | 1.8 pCi/L | 1.1 | Low | EPA Zone 2 | 5 |
| Livingston County | 1.8 pCi/L | 1.2 | Low | EPA Zone 2 | 7 |
| Todd County | 1.7 pCi/L | 1.5 | Low | EPA Zone 2 | 5 |
| Campbell County | 1.7 pCi/L | 1.3 | Low | EPA Zone 2 | 9 |
| Ballard County | 1.7 pCi/L | 0.9 | Low | EPA Zone 3 | 4 |
| Calloway County | 1.7 pCi/L | 1.0 | Low | EPA Zone 3 | 6 |
| Marshall County | 1.6 pCi/L | 1.1 | Low | EPA Zone 3 | 4 |
| Carlisle County | 1.6 pCi/L | 0.9 | Low | EPA Zone 3 | 3 |
| Fulton County | 1.5 pCi/L | 0.9 | Low | EPA Zone 3 | 2 |
| Graves County | 1.5 pCi/L | 0.9 | Low | EPA Zone 3 | 10 |
| Hickman County | 1.5 pCi/L | 0.9 | Low | EPA Zone 3 | 2 |
| McCracken County | 1.5 pCi/L | 0.9 | Low | EPA Zone 3 | 3 |
Radon levels in Kentucky cities
The 4 most-populous Kentucky 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 |
|---|---|---|---|---|---|
| Louisville | 622,981 | 2.3 pCi/L | 1.4 | Moderate | 0% |
| Lexington | 320,154 | 3.0 pCi/L | 2.0 | Moderate | 21% |
| Bowling Green | 76,212 | 2.9 pCi/L | 3.5 | Moderate | 0% |
| Owensboro | 60,140 | 1.8 pCi/L | 1.1 | Low | 0% |
Highest-radon ZIP codes in Kentucky
The 10 Kentucky ZIP codes with the highest predicted basement average (model estimate), out of 705 modeled. A ZIP average is still an area figure - neighboring homes routinely test several pCi/L apart.
| ZIP | County | Predicted basement | Upstairs | Grade |
|---|---|---|---|---|
| 40502 | Fayette County | 4.8 pCi/L | 3.4 | High |
| 40503 | Fayette County | 4.5 pCi/L | 2.9 | High |
| 42749 | Hart County | 4.1 pCi/L | 2.1 | High |
| 40504 | Fayette County | 4.1 pCi/L | 2.9 | High |
| 42103 | Warren County | 3.9 pCi/L | 4.9 | Moderate |
| 40356 | Jessamine County | 3.8 pCi/L | 2.0 | Moderate |
| 40383 | Woodford County | 3.7 pCi/L | 2.3 | Moderate |
| 40511 | Fayette County | 3.7 pCi/L | 2.6 | Moderate |
| 40165 | Bullitt County | 3.6 pCi/L | 2.0 | Moderate |
| 40004 | Nelson County | 3.6 pCi/L | 1.9 | Moderate |
Kentucky radon questions
- Is radon high in Kentucky?
- Kentucky's population-weighted predicted basement average is 2.5 pCi/L, about 1.4× the US average of 1.8. 0 of its 120 modeled counties are predicted at or above the EPA action level of 4 pCi/L, 100 are in the 2-4 "consider fixing" range and 20 are below 2. 0.6% of Kentucky ZIP codes are predicted at 4 or higher.
- Which Kentucky county has the highest radon?
- Jessamine County has the highest predicted basement average in Kentucky at 3.7 pCi/L (EPA Zone 1). The lowest is McCracken County at 1.5 pCi/L. These are area figures; individual homes in any county can test far higher.
- How many EPA Zone 1 counties are in Kentucky?
- 30 of Kentucky's 120 counties (25%) are EPA Zone 1 (highest potential), 82 are Zone 2 and 8 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 Kentucky?
- Yes - with some urgency. Kentucky's predicted average is in the moderate range, and 71.8% 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.
Kentucky radon program
State programs keep lists of certified testers and mitigators and sometimes run kit programs. We link only pages we could verify, and Kentucky's program page did not respond when we checked, so start from the EPA state radon contacts page. Then read how to test and what mitigation costs.