Texas Radon Levels
0Zone 1 (High)
39Zone 2 (Moderate)
215Zone 3 (Low)
No counties in Texas are classified as Zone 1 (highest risk), but 39 counties are Zone 2 (moderate potential). The EPA recommends testing all homes regardless of zone classification, as elevated radon can occur in any zone.
| County | EPA Zone | Risk Level |
|---|---|---|
| Anderson County | Zone 3 | Lowest Potential |
| Andrews County | Zone 3 | Lowest Potential |
| Angelina County | Zone 3 | Lowest Potential |
| Aransas County | Zone 3 | Lowest Potential |
| Archer County | Zone 3 | Lowest Potential |
| Armstrong County | Zone 2 | Moderate Potential |
| Atascosa County | Zone 3 | Lowest Potential |
| Austin County | Zone 3 | Lowest Potential |
| Bailey County | Zone 2 | Moderate Potential |
| Bandera County | Zone 3 | Lowest Potential |
| Bastrop County | Zone 3 | Lowest Potential |
| Baylor County | Zone 3 | Lowest Potential |
| Bee County | Zone 3 | Lowest Potential |
| Bell County | Zone 3 | Lowest Potential |
| Bexar County | Zone 3 | Lowest Potential |
| Blanco County | Zone 3 | Lowest Potential |
| Borden County | Zone 3 | Lowest Potential |
| Bosque County | Zone 3 | Lowest Potential |
| Bowie County | Zone 3 | Lowest Potential |
| Brazoria County | Zone 3 | Lowest Potential |
| Brazos County | Zone 3 | Lowest Potential |
| Brewster County | Zone 2 | Moderate Potential |
| Briscoe County | Zone 3 | Lowest Potential |
| Brooks County | Zone 3 | Lowest Potential |
| Brown County | Zone 3 | Lowest Potential |
| Burleson County | Zone 3 | Lowest Potential |
| Burnet County | Zone 3 | Lowest Potential |
| Caldwell County | Zone 3 | Lowest Potential |
| Calhoun County | Zone 3 | Lowest Potential |
| Callahan County | Zone 3 | Lowest Potential |
| Cameron County | Zone 3 | Lowest Potential |
| Camp County | Zone 3 | Lowest Potential |
| Carson County | Zone 2 | Moderate Potential |
| Cass County | Zone 3 | Lowest Potential |
| Castro County | Zone 2 | Moderate Potential |
| Chambers County | Zone 3 | Lowest Potential |
| Cherokee County | Zone 3 | Lowest Potential |
| Childress County | Zone 3 | Lowest Potential |
| Clay County | Zone 3 | Lowest Potential |
| Cochran County | Zone 3 | Lowest Potential |
| Coke County | Zone 3 | Lowest Potential |
| Coleman County | Zone 3 | Lowest Potential |
| Collin County | Zone 3 | Lowest Potential |
| Collingsworth County | Zone 3 | Lowest Potential |
| Colorado County | Zone 3 | Lowest Potential |
| Comal County | Zone 3 | Lowest Potential |
| Comanche County | Zone 3 | Lowest Potential |
| Concho County | Zone 3 | Lowest Potential |
| Cooke County | Zone 3 | Lowest Potential |
| Coryell County | Zone 3 | Lowest Potential |
| Cottle County | Zone 3 | Lowest Potential |
| Crane County | Zone 3 | Lowest Potential |
| Crockett County | Zone 3 | Lowest Potential |
| Crosby County | Zone 2 | Moderate Potential |
| Culberson County | Zone 2 | Moderate Potential |
| Dallam County | Zone 2 | Moderate Potential |
| Dallas County | Zone 3 | Lowest Potential |
| Dawson County | Zone 3 | Lowest Potential |
| Deaf Smith County | Zone 2 | Moderate Potential |
| Delta County | Zone 3 | Lowest Potential |
| Denton County | Zone 3 | Lowest Potential |
| DeWitt County | Zone 3 | Lowest Potential |
| Dickens County | Zone 3 | Lowest Potential |
| Dimmit County | Zone 3 | Lowest Potential |
| Donley County | Zone 2 | Moderate Potential |
| Duval County | Zone 3 | Lowest Potential |
| Eastland County | Zone 3 | Lowest Potential |
| Ector County | Zone 3 | Lowest Potential |
| Edwards County | Zone 3 | Lowest Potential |
| Ellis County | Zone 3 | Lowest Potential |
| El Paso County | Zone 3 | Lowest Potential |
| Erath County | Zone 3 | Lowest Potential |
| Falls County | Zone 3 | Lowest Potential |
| Fannin County | Zone 3 | Lowest Potential |
| Fayette County | Zone 3 | Lowest Potential |
| Fisher County | Zone 3 | Lowest Potential |
| Floyd County | Zone 2 | Moderate Potential |
| Foard County | Zone 3 | Lowest Potential |
| Fort Bend County | Zone 3 | Lowest Potential |
| Franklin County | Zone 3 | Lowest Potential |
| Freestone County | Zone 3 | Lowest Potential |
| Frio County | Zone 3 | Lowest Potential |
| Gaines County | Zone 3 | Lowest Potential |
| Galveston County | Zone 3 | Lowest Potential |
| Garza County | Zone 2 | Moderate Potential |
| Gillespie County | Zone 3 | Lowest Potential |
| Glasscock County | Zone 3 | Lowest Potential |
| Goliad County | Zone 3 | Lowest Potential |
| Gonzales County | Zone 3 | Lowest Potential |
| Gray County | Zone 2 | Moderate Potential |
| Grayson County | Zone 3 | Lowest Potential |
| Gregg County | Zone 3 | Lowest Potential |
| Grimes County | Zone 3 | Lowest Potential |
| Guadalupe County | Zone 3 | Lowest Potential |
| Hale County | Zone 2 | Moderate Potential |
| Hall County | Zone 3 | Lowest Potential |
| Hamilton County | Zone 3 | Lowest Potential |
| Hansford County | Zone 2 | Moderate Potential |
| Hardeman County | Zone 3 | Lowest Potential |
| Hardin County | Zone 3 | Lowest Potential |
| Harris County | Zone 3 | Lowest Potential |
| Harrison County | Zone 3 | Lowest Potential |
| Hartley County | Zone 2 | Moderate Potential |
| Haskell County | Zone 3 | Lowest Potential |
| Hays County | Zone 3 | Lowest Potential |
| Hemphill County | Zone 2 | Moderate Potential |
| Henderson County | Zone 3 | Lowest Potential |
| Hidalgo County | Zone 3 | Lowest Potential |
| Hill County | Zone 3 | Lowest Potential |
| Hockley County | Zone 2 | Moderate Potential |
| Hood County | Zone 3 | Lowest Potential |
| Hopkins County | Zone 3 | Lowest Potential |
| Houston County | Zone 3 | Lowest Potential |
| Howard County | Zone 3 | Lowest Potential |
| Hudspeth County | Zone 2 | Moderate Potential |
| Hunt County | Zone 3 | Lowest Potential |
| Hutchinson County | Zone 2 | Moderate Potential |
| Irion County | Zone 3 | Lowest Potential |
| Jack County | Zone 3 | Lowest Potential |
| Jackson County | Zone 3 | Lowest Potential |
| Jasper County | Zone 3 | Lowest Potential |
| Jeff Davis County | Zone 2 | Moderate Potential |
| Jefferson County | Zone 3 | Lowest Potential |
| Jim Hogg County | Zone 3 | Lowest Potential |
| Jim Wells County | Zone 3 | Lowest Potential |
| Johnson County | Zone 3 | Lowest Potential |
| Jones County | Zone 3 | Lowest Potential |
| Karnes County | Zone 3 | Lowest Potential |
| Kaufman County | Zone 3 | Lowest Potential |
| Kendall County | Zone 3 | Lowest Potential |
| Kenedy County | Zone 3 | Lowest Potential |
| Kent County | Zone 3 | Lowest Potential |
| Kerr County | Zone 3 | Lowest Potential |
| Kimble County | Zone 3 | Lowest Potential |
| King County | Zone 3 | Lowest Potential |
| Kinney County | Zone 3 | Lowest Potential |
| Kleberg County | Zone 3 | Lowest Potential |
| Knox County | Zone 3 | Lowest Potential |
| Lamar County | Zone 3 | Lowest Potential |
| Lamb County | Zone 2 | Moderate Potential |
| Lampasas County | Zone 3 | Lowest Potential |
| La Salle County | Zone 3 | Lowest Potential |
| Lavaca County | Zone 3 | Lowest Potential |
| Lee County | Zone 3 | Lowest Potential |
| Leon County | Zone 3 | Lowest Potential |
| Liberty County | Zone 3 | Lowest Potential |
| Limestone County | Zone 3 | Lowest Potential |
| Lipscomb County | Zone 2 | Moderate Potential |
| Live Oak County | Zone 3 | Lowest Potential |
| Llano County | Zone 2 | Moderate Potential |
| Loving County | Zone 3 | Lowest Potential |
| Lubbock County | Zone 2 | Moderate Potential |
| Lynn County | Zone 2 | Moderate Potential |
| McCulloch County | Zone 3 | Lowest Potential |
| McLennan County | Zone 3 | Lowest Potential |
| McMullen County | Zone 3 | Lowest Potential |
| Madison County | Zone 3 | Lowest Potential |
| Marion County | Zone 3 | Lowest Potential |
| Martin County | Zone 3 | Lowest Potential |
| Mason County | Zone 2 | Moderate Potential |
| Matagorda County | Zone 3 | Lowest Potential |
| Maverick County | Zone 3 | Lowest Potential |
| Medina County | Zone 3 | Lowest Potential |
| Menard County | Zone 3 | Lowest Potential |
| Midland County | Zone 3 | Lowest Potential |
| Milam County | Zone 3 | Lowest Potential |
| Mills County | Zone 3 | Lowest Potential |
| Mitchell County | Zone 3 | Lowest Potential |
| Montague County | Zone 3 | Lowest Potential |
| Montgomery County | Zone 3 | Lowest Potential |
| Moore County | Zone 2 | Moderate Potential |
| Morris County | Zone 3 | Lowest Potential |
| Motley County | Zone 3 | Lowest Potential |
| Nacogdoches County | Zone 3 | Lowest Potential |
| Navarro County | Zone 3 | Lowest Potential |
| Newton County | Zone 3 | Lowest Potential |
| Nolan County | Zone 3 | Lowest Potential |
| Nueces County | Zone 3 | Lowest Potential |
| Ochiltree County | Zone 2 | Moderate Potential |
| Oldham County | Zone 2 | Moderate Potential |
| Orange County | Zone 3 | Lowest Potential |
| Palo Pinto County | Zone 3 | Lowest Potential |
| Panola County | Zone 3 | Lowest Potential |
| Parker County | Zone 3 | Lowest Potential |
| Parmer County | Zone 2 | Moderate Potential |
| Pecos County | Zone 3 | Lowest Potential |
| Polk County | Zone 3 | Lowest Potential |
| Potter County | Zone 2 | Moderate Potential |
| Presidio County | Zone 2 | Moderate Potential |
| Rains County | Zone 3 | Lowest Potential |
| Randall County | Zone 2 | Moderate Potential |
| Reagan County | Zone 3 | Lowest Potential |
| Real County | Zone 3 | Lowest Potential |
| Red River County | Zone 3 | Lowest Potential |
| Reeves County | Zone 2 | Moderate Potential |
| Refugio County | Zone 3 | Lowest Potential |
| Roberts County | Zone 2 | Moderate Potential |
| Robertson County | Zone 3 | Lowest Potential |
| Rockwall County | Zone 3 | Lowest Potential |
| Runnels County | Zone 3 | Lowest Potential |
| Rusk County | Zone 3 | Lowest Potential |
| Sabine County | Zone 3 | Lowest Potential |
| San Augustine County | Zone 3 | Lowest Potential |
| San Jacinto County | Zone 3 | Lowest Potential |
| San Patricio County | Zone 3 | Lowest Potential |
| San Saba County | Zone 3 | Lowest Potential |
| Schleicher County | Zone 3 | Lowest Potential |
| Scurry County | Zone 3 | Lowest Potential |
| Shackelford County | Zone 3 | Lowest Potential |
| Shelby County | Zone 3 | Lowest Potential |
| Sherman County | Zone 2 | Moderate Potential |
| Smith County | Zone 3 | Lowest Potential |
| Somervell County | Zone 3 | Lowest Potential |
| Starr County | Zone 3 | Lowest Potential |
| Stephens County | Zone 3 | Lowest Potential |
| Sterling County | Zone 3 | Lowest Potential |
| Stonewall County | Zone 3 | Lowest Potential |
| Sutton County | Zone 3 | Lowest Potential |
| Swisher County | Zone 2 | Moderate Potential |
| Tarrant County | Zone 3 | Lowest Potential |
| Taylor County | Zone 3 | Lowest Potential |
| Terrell County | Zone 2 | Moderate Potential |
| Terry County | Zone 3 | Lowest Potential |
| Throckmorton County | Zone 3 | Lowest Potential |
| Titus County | Zone 3 | Lowest Potential |
| Tom Green County | Zone 3 | Lowest Potential |
| Travis County | Zone 3 | Lowest Potential |
| Trinity County | Zone 3 | Lowest Potential |
| Tyler County | Zone 3 | Lowest Potential |
| Upshur County | Zone 3 | Lowest Potential |
| Upton County | Zone 3 | Lowest Potential |
| Uvalde County | Zone 3 | Lowest Potential |
| Val Verde County | Zone 3 | Lowest Potential |
| Van Zandt County | Zone 3 | Lowest Potential |
| Victoria County | Zone 3 | Lowest Potential |
| Walker County | Zone 3 | Lowest Potential |
| Waller County | Zone 3 | Lowest Potential |
| Ward County | Zone 3 | Lowest Potential |
| Washington County | Zone 3 | Lowest Potential |
| Webb County | Zone 3 | Lowest Potential |
| Wharton County | Zone 3 | Lowest Potential |
| Wheeler County | Zone 3 | Lowest Potential |
| Wichita County | Zone 3 | Lowest Potential |
| Wilbarger County | Zone 3 | Lowest Potential |
| Willacy County | Zone 3 | Lowest Potential |
| Williamson County | Zone 3 | Lowest Potential |
| Wilson County | Zone 3 | Lowest Potential |
| Winkler County | Zone 3 | Lowest Potential |
| Wise County | Zone 3 | Lowest Potential |
| Wood County | Zone 3 | Lowest Potential |
| Yoakum County | Zone 3 | Lowest Potential |
| Young County | Zone 3 | Lowest Potential |
| Zapata County | Zone 3 | Lowest Potential |
| Zavala County | Zone 3 | Lowest Potential |