Radon in Florida: radon map by county
EPA's Map of Radon Zones puts 0 of Florida's 67 counties in Zone 1 (predicted average indoor radon above 4 pCi/L), 9 in Zone 2 and 58 in Zone 3. Of 46,241 building tests that radon laboratories reported for 2008 to 2017, 23.1% were at or above EPA's 4 pCi/L action level, against 36.5% nationally (number 32 of 42 states with 1,000+ tests). The highest county share is Marion County (42.9% of 695 tests).
Radon by county in Florida
| County | EPA zone | Lab tests | Median | 4+ pCi/L |
|---|---|---|---|---|
| Alachua County | Zone 2 | 1,941 | 2.9 | 35.2% |
| Baker County | Zone 3 | 1 | 1.0 | 0% |
| Bay County | Zone 3 | 10 | 0.9 | 12.5% |
| Bradford County | Zone 3 | 4 | 2.0 | 0% |
| Brevard County | Zone 3 | 624 | 0.8 | 2.6% |
| Broward County | Zone 3 | 427 | 1.1 | 7.5% |
| Calhoun County | Zone 3 | n/a | n/a | n/a |
| Charlotte County | Zone 3 | 139 | 2.2 | 25.3% |
| Citrus County | Zone 2 | 144 | 1.6 | 9.9% |
| Clay County | Zone 3 | 20 | 1.2 | 13% |
| Collier County | Zone 3 | 17,702 | 2.4 | 25.9% |
| Columbia County | Zone 2 | 20 | 1.0 | 6.7% |
| DeSoto County | Zone 3 | 40 | 0.6 | 4.4% |
| Dixie County | Zone 3 | 1 | 5.4 | 100% |
| Duval County | Zone 3 | 364 | 0.5 | 1.3% |
| Escambia County | Zone 3 | 40 | 0.9 | 1.5% |
| Flagler County | Zone 3 | 12 | 1.2 | 4.8% |
| Franklin County | Zone 3 | 3 | 0.1 | 0% |
| Gadsden County | Zone 3 | 134 | 1.2 | 6.3% |
| Gilchrist County | Zone 3 | 8 | 0.7 | 0% |
| Glades County | Zone 3 | 2 | 1.7 | 0% |
| Gulf County | Zone 3 | n/a | n/a | n/a |
| Hamilton County | Zone 3 | n/a | n/a | n/a |
| Hardee County | Zone 3 | 1 | 1.9 | 0% |
| Hendry County | Zone 3 | 7 | 1.0 | 7.1% |
| Hernando County | Zone 3 | 188 | 0.8 | 1.8% |
| Highlands County | Zone 3 | 24 | 0.7 | 0% |
| Hillsborough County | Zone 2 | 2,806 | 1.3 | 18.1% |
| Holmes County | Zone 3 | 2 | 0.6 | 0% |
| Indian River County | Zone 3 | 136 | 0.7 | 2.5% |
| Jackson County | Zone 3 | 54 | 0.7 | 6% |
| Jefferson County | Zone 3 | 48 | 1.4 | 6.1% |
| Lafayette County | Zone 3 | n/a | n/a | n/a |
| Lake County | Zone 3 | 54 | 0.9 | 3.1% |
| Lee County | Zone 3 | 10,708 | 2.4 | 25.1% |
| Leon County | Zone 2 | 5,185 | 2.2 | 23.3% |
| Levy County | Zone 3 | 22 | 1.9 | 13% |
| Liberty County | Zone 3 | n/a | n/a | n/a |
| Madison County | Zone 3 | 6 | 0.6 | 12.5% |
| Manatee County | Zone 3 | 426 | 1.7 | 12.9% |
| Marion County | Zone 2 | 695 | 3.3 | 42.9% |
| Martin County | Zone 3 | 160 | 0.8 | 10.7% |
| Miami-Dade County | Zone 2 | 451 | 1.6 | 19.1% |
| Monroe County | Zone 3 | 11 | 1.6 | 20% |
| Nassau County | Zone 3 | 36 | 0.7 | 2% |
| Okaloosa County | Zone 3 | 25 | 0.6 | 2.9% |
| Okeechobee County | Zone 3 | 3 | 1.5 | 0% |
| Orange County | Zone 3 | 144 | 1.1 | 4% |
| Osceola County | Zone 3 | 205 | 0.8 | 0.8% |
| Palm Beach County | Zone 3 | 635 | 1.0 | 7.8% |
| Pasco County | Zone 3 | 120 | 0.8 | 10.4% |
| Pinellas County | Zone 3 | 159 | 0.8 | 11.8% |
| Polk County | Zone 2 | 507 | 2.1 | 28.4% |
| Putnam County | Zone 3 | 78 | 0.1 | 1.1% |
| Santa Rosa County | Zone 3 | 33 | 0.8 | 2% |
| Sarasota County | Zone 3 | 724 | 1.8 | 18.2% |
| Seminole County | Zone 3 | 333 | 0.7 | 4.2% |
| St. Johns County | Zone 3 | 34 | 0.7 | 6% |
| St. Lucie County | Zone 3 | 28 | 0.1 | 0% |
| Sumter County | Zone 3 | 51 | 1.7 | 25.9% |
| Suwannee County | Zone 3 | 21 | 1.1 | 0% |
| Taylor County | Zone 3 | 3 | 2.1 | 0% |
| Union County | Zone 2 | 2 | 8.5 | 66.7% |
| Volusia County | Zone 3 | 394 | 0.7 | 1.8% |
| Wakulla County | Zone 3 | 76 | 1.5 | 8.9% |
| Walton County | Zone 3 | 9 | 1.4 | 20% |
| Washington County | Zone 3 | 1 | 0.9 | 0% |
Lab tests: buildings tested by radon laboratories, 2008 to 2017; median in pCi/L; “4+ pCi/L” is the share of tests at or above EPA's action level. n/a: no value on file (no tests, or too few to report).
What the zones mean
Zone 1 counties have a predicted average indoor radon screening level above 4 pCi/L, Zone 2 from 2 to 4 pCi/L and Zone 3 below 2 pCi/L. The prediction is from 1993 indoor measurements, geology, aerial radioactivity, soils and foundation types. EPA: “This map should not be used to determine if individual homes need to be tested.” EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, because there is no known safe level of exposure.
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Radon in Florida: questions
What radon zone is Florida?
EPA's 1993 map does not give states one zone; it zones each county. In Florida, 0 counties are Zone 1, 9 Zone 2 and 58 Zone 3. EPA says the map "should not be used to determine if individual homes need to be tested".
Which Florida counties have the highest radon levels?
By the share of laboratory tests at or above 4 pCi/L for 2008 to 2017 (counties with 20 or more tests): Marion County 42.9% (median 3.3 pCi/L, 695 tests); Alachua County 35.2% (median 2.9 pCi/L, 1,941 tests); Polk County 28.4% (median 2.1 pCi/L, 507 tests); Collier County 25.9% (median 2.4 pCi/L, 17,702 tests); Sumter County 25.9% (median 1.7 pCi/L, 51 tests).
How common is high radon in Florida?
23.1% of the 46,241 tests in the laboratory data for Florida (2008 to 2017) were at or above 4 pCi/L; the national share was 36.5%. Buildings are tested by choice, often because of a sale or a concern, so the share describes the tests on file, not every home.
Does Florida publish its own radon test data?
Florida's radon program reports county test results; the latest year with county results is 2023, shown on each county page.
Should I test for radon in Florida?
Yes. EPA recommends testing every home no matter where it is, fixing it at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, because there is no known safe level of radon exposure.
States bordering Florida
Other free hazard lookups
- Radon by county and ZIP codeEPA radon zone and the radon test results on file for any county, ZIP code or address.
- Fault lines near an addressUSGS-mapped earthquake faults within 5 miles, their age and slip rate, and the USGS seismic hazard value.
- Power lines near an addressHigh-voltage transmission lines within 1 mile from federal maps, with voltage and distance.
- Flood zone lookupThe FEMA flood zone mapped at any US address. Not an official flood zone determination.
- Superfund sites near an addressThe nearest EPA Superfund (NPL) sites and their status.
All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).
Superfund sites in Florida · Radon map of every state
Data compiled 2026-10-20. County-level screening information, not a radon measurement of any building.