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Radon Levels in Lake County, Florida

EPA puts Lake County in Zone 3, its lowest radon zone, and most reported tests there come back low, though 0.0% of 159 (2023) reached 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    0.0%

    18.5 pts below FL

    Lake
    0.0%
    Florida
    18.5%

    159 tests, 2023

  • Median result

    0.6pCi/L

    Below action level

    Lake
    0.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    159

    19th of 30 by tests

    Lake
    159
    Broward
    2,165

    Reported to CDC before any fix, 2023

  • EPA radon zone

    Zone 3

    Lower potential

    1. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

  • Rank in Florida

    23 of 30

    Middle half

    Lake
    0.0%
    Marion
    44.5%

    By share, of 30 with 30+ tests

Read a result for Lake County

Starts at Lake County's median, 0.6 pCi/L

0.6pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 0.6 pCi/L

Below 2 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Lake County's median reported result, 2023.

Interpret this reading

The data

Lake County, At a glance

Lake County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Lake County as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

USGS geologic potential: Low across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Lake County, 2023

Share of reported tests at or above 4 pCi/L, by year, Lake County
Share of reported tests at or above 4 pCi/L, by year, Lake County
YearShare of reported tests at or above 4 pCi/L
20140.0%
20150.0%
20160.0%
20170.0%
20180.0%
20190.0%
20201.2%
20210.0%
20220.0%
20230.0%

2023: 0.0%. Across these years the share ran from 0.0% to 1.2%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 159 tests reported to CDC for Lake County over 2023, many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.

Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Lake County, Compared

Lake County radon figures, compared

Calculated by Radon411

Only 0 of 159 radon tests reported for Lake County in 2023 reached 4 pCi/L (0.0%). The median result, 0.6 pCi/L, sits below 2, well under EPA's 4 pCi/L action level, and the top reported result was 3.1 pCi/L.

Across 49 Florida counties pooled together, 18.5% of tests reached that level, so Lake County runs 18.5 points below its state. Against the national pool of 33.4%, the gap is 33.4 points lower. Its place in the state: 23rd of 30 Florida counties with 30 or more tests for the same period.

Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 0.0% share point the same way here. Of 6 neighbours with a figure, all 6 reported a larger share at or above 4 pCi/L; the spread is 1.2% (Volusia County) to 44.5% (Marion County).

Below the action level, 153 tests (96.2%) came in under 2 pCi/L, against 57.3% statewide, and 6 tests (3.8%) fell between 2 and 4, against 24.2% statewide. Over 5 years of annual figures the share held within 2 points, from 0.0% in 2016 to 0.0% in 2023; its peak was 1.2% in 2020. USGS geology rates 100% of the county's land low radon potential.

The busiest year on file was 2022, with 168 tests reported; the quietest, 2015, had 3.

Share of reported tests at or above 4 pCi/L by year, Lake County against Florida2016 to 2023, years with 30 or more tests: Lake County 0.0% to 0.0%, the state's pooled share 18.5% in 2023.
Lake CountyFlorida, pooled
Share of reported tests at or above 4 pCi/L by year, Lake County against Florida: data table
YearTestsLake County, at or above 4 pCi/LFlorida, pooled
2016500.0%24.3%
2020861.2%23.2%
2021410.0%15.4%
20221680.0%22.8%
20231590.0%18.5%
Lake County against Florida, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Lake County
Lake County1590.0%0.6 pCi/LThis county
Florida, pooled49 counties, pooled16,58918.5%Not pooled+18.5 points
United States, pooled642 counties, pooled128,74033.4%Not pooled+33.4 points
Palm Beach Countyhighest in the state1,52640.1%3.0 pCi/L+40.1 points
Clay Countylowest in the state360.0%1.0 pCi/LLevel
Marion County, FLborders it18244.5%3.6 pCi/L+44.5 points
Polk County, FLborders it13611.0%1.1 pCi/L+11.0 points
Orange County, FLborders it1,1079.5%0.9 pCi/L+9.5 points
Seminole County, FLborders it1901.6%0.6 pCi/L+1.6 points
Osceola County, FLborders it701.4%1.2 pCi/L+1.4 points
Volusia County, FLborders it1631.2%0.6 pCi/L+1.2 points
Sumter County, FLborders it120.0%0.9 pCi/LLevel
Where Lake County's reported results fell, 2023, beside Florida and the United States
ResultLake County testsLake County shareFlorida shareU.S. shareAgainst Florida
Under 2 pCi/L15396.2%57.3%41.4%+38.9 points
2 to 4 pCi/L63.8%24.2%25.2%−20.4 points
4 pCi/L and above00.0%18.5%33.4%−18.5 points
Lake County ranked among the 30 Florida counties with 30 or more tests, by share at or above 4 pCi/L, 2023
CountyRankTestsAt or above 4 pCi/LMedian
Seminole County19 of 301901.6%0.6 pCi/L
Osceola County20 of 30701.4%1.2 pCi/L
Volusia County21 of 301631.2%0.6 pCi/L
Pasco County22 of 301640.6%0.8 pCi/L
Brevard County23 of 302050.0%0.7 pCi/L
Lake County23 of 301590.0%0.6 pCi/L
Bay County23 of 301330.0%0.4 pCi/L
St. Johns County23 of 30960.0%0.7 pCi/L
Nassau County23 of 30900.0%0.7 pCi/L
Escambia County23 of 30590.0%0.4 pCi/L
Baker County23 of 30480.0%1.1 pCi/L
Lake County radon tests by year, against Florida's pooled share
YearTestsAt or above 4 pCi/LMedianHighestFlorida, pooledChange from the row before
20231590.0%0.6 pCi/L3.1 pCi/L18.5%Level
20221680.0%0.6 pCi/L3.6 pCi/L22.8%Level
2021410.0%0.9 pCi/L1.9 pCi/L15.4%−1.2 points
2020861.2%0.8 pCi/L17.0 pCi/L23.2%+1.2 points
2019140.0%0.5 pCi/L2.4 pCi/L29.6%Level
2018270.0%0.8 pCi/L3.5 pCi/L23.5%Level
2017110.0%0.7 pCi/L1.2 pCi/L21.7%Level
2016500.0%1.0 pCi/L3.0 pCi/L24.3%Level
201530.0%0.4 pCi/L2.1 pCi/L26.5%Level
2014280.0%1.3 pCi/L3.2 pCi/L25.7%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Lake County, Geology

The ground under Lake County

Predicted

USGS's geologic map puts all of Lake County's mapped land in one class: low radon potential. All of it lies in the area the map calls Gulf/Atlantic Lowland and Central Highland, to which USGS gives a radon index of 6, in the low band (5 to 8).

USGS's geologic areas under Lake County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Gulf/Atlantic Lowland and Central Highlandsand, silt, clay, gravelLow6100%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Lake County beside the ground around it

Across Florida 7.1% of the land is rated moderate; none of Lake County's is. Of the 7 counties that border it, 3 have more moderate-potential ground, Polk County the most at 33.7%.

Share of land by USGS radon potential: Lake County, the 7 counties bordering it and Florida
AreaEPA zoneLow potentialModerate potentialHigh potential
Lake CountyZone 3100%NoneNone
Seminole CountyZone 3100%NoneNone
Orange CountyZone 3100%NoneNone
Sumter CountyZone 380.6%19.4%None
Volusia CountyZone 398.3%NoneNone
Marion CountyZone 268.6%31.4%None
Polk CountyZone 266.3%33.7%None
Osceola CountyZone 3100%NoneNone
Florida67 counties, pooled by land areaVaries89.7%7.1%None

The map rates the ground, not the air in any home.

Local help

Lake County, Local resources

Radon testing and mitigation in Lake County

What Florida's program says
Phone
850-245-4288
Email
PHtoxicology@FLhealth.gov
Licensing of radon professionals
Florida Statutes require the certification of businesses and individuals providing radon services or any other radon related activity.

What it means

Lake County, Questions

Questions about radon in Lake County

Are radon levels high in Lake County?

In 2023, 0.0% of the radon tests reported to CDC for Lake County, Florida were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.6 pCi/L. Of 30 Florida counties with 30 or more tests for the same period, 22 reported a higher share; pooled, the state comes to 18.5%.

Which counties border Lake County?

Lake County borders 7 counties: Seminole County, Orange County, Sumter County, Volusia County, Marion County, Polk County and Osceola County.

Products

Lake County, Products

Testing a home in Lake County

In Lake County, 0.0% of 159 tests reported to CDC in 2023 reached 4 pCi/L, against 18.5% pooled across Florida. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Lake County.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Lake County homes, compared

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Lake County, Bordering counties

Counties bordering Lake County

Calculated by Radon411

Lake County, Cities and towns

Cities and towns in Lake County

Lake County is growing: the Census Bureau puts it at 456,068 residents on July 1, 2025, up 18.1% from 386,221 in 2020. That works out to 479 people per square mile of land. No town dominates: Clermont, the largest, has 52,812 residents, 11.6% of the total. Together its 14 incorporated places hold 55.4% of those residents; the other 44.6% live outside any of them. Reported testing is thin here: 159 tests over 2023, or 0.3 for every 1,000 residents (2025 estimate), where Florida as a whole comes to 0.7.

From Clermont to Montverde, CDC publishes no figure by town: each reads Lake County's.

The 12 largest cities and towns in Lake County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Clermont52,812+22.0%11.6%
Leesburg38,905+43.3%8.5%
Groveland25,526+35.3%5.6%
Eustis25,483+9.7%5.6%
Tavares22,490+18.3%4.9%
Minneola21,064+48.3%4.6%
Mount Dora18,791+14.9%4.1%
Lady Lake17,496+9.0%3.8%
Mascotte10,150+50.7%2.2%
Fruitland Park9,543+13.1%2.1%
Umatilla4,199+12.0%0.9%
Astatula2,314+21.7%0.5%
  • Howey-in-the-Hills
  • Montverde

14 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).

Lake County, Homes

Homes in Lake County

Of Lake County's 182,666 homes, 67% are detached houses, against 55% across Florida; 17% are mobile homes. Much of Lake County is recent building: 42% of its homes have gone up since 2000 and the middle year built is 1996, against 1988 for Florida. Owners live in 77% of the occupied homes (Florida: 67%), so for most households a test and a fix are their own to order.

Homes in Lake County, Florida, 2019 to 2023
HomesLake CountyFlorida
Housing units182,66610,082,356
Detached houses67%55%
In buildings of 5 or more10%25%
Mobile homes17%8%
Built before 19608%10%
Built since 200042%30%
Middle year built19961988
Owner-occupied77%67%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.