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Radon Levels in Hillsborough County, Florida

EPA puts Hillsborough County in Zone 2, its middle radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

Predicted
Zone 2Moderate predicted potential
Measured
7.5%of 984 tests reported to CDC (2023) were at or above 4 pCi/L
Your home
Test to knowNo area figure here is a reading of your home.

The data

Hillsborough County, At a glance

Hillsborough County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.

What EPA predicts hereScreening level, geology

EPA predicts an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³) across the county as a whole.

USGS geologic potential: Low across 56% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Hillsborough County, 2023

Tests reported
984
At or above 4 pCi/L
7.5%
Median result
0.9 pCi/L
Reported results by concentration band, Hillsborough County, 2023
Under 2 pCi/L: 83%2 to 4 pCi/L: 10%4 pCi/L and above: 7%

Of 984 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Hillsborough County, 2023: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L81582.8%
2 to 4 pCi/L959.7%
4 pCi/L and above747.5%

CDC publishes this figure only for counties here, so there is no state or national number to compare Hillsborough County, Florida with.

What these figures count

Distribution of radon tests reported to CDC, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.

The figures at the top are for 2023: a percentage there is a share of radon tests reported to CDC for Hillsborough County in 2023, and a percentage in a view below is a share of the tests reported for the year or period it names. It is not a share of homes in Hillsborough County, and it is not a random sample: it counts only the tests people chose to run and that were reported.

CDC works out the shares and the median over pre-mitigation tests, counting a test not marked as before or after mitigation as one of them (984 for 2023). The median is the middle result of those tests, not of buildings. CDC also reports the number of buildings tested (929), a different count, so the two totals are not interchangeable.

Hillsborough County's own published CDC figures beside those of the counties that border it, for the same period.

Each figure is that county’s own published CDC figure for 2023, counting radon tests reported to CDC, not homes. Hillsborough County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. No published CDC figure for 2023: Hardee County, FL. Every Florida county’s own figure is in the Florida county table.

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

Radon Action Brief

National Radon Action MonthPre-sale

Hillsborough County's radon brief, in one dated file.

  • Your area's radon record, explained.
  • Your plan to test this week.
  • Fix costs and pros near you.

Save 64%Sale price: $8.99Price after the sale: $25Ends Jan 31Then $25

Get the Hillsborough County BriefSee a free sample

Area data, not a test of the building.

Local help

Hillsborough County, Local resources

Radon testing and mitigation in Hillsborough County

Who tests and fixes radon in Hillsborough County: listed businesses, Florida's radon program and test kits.

What it means

Hillsborough County, Questions

Questions about radon in Hillsborough County

Common questions

8 questions, answered from the figures above

How do I get a radon test in Hillsborough County?

EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No radon testing business listed on Radon411 has an address in Hillsborough County or names it as a service area yet. The Florida radon program is the place to ask about certified testers and any test kit offer it runs.

Radon testing: how to test a homeRadon test kits comparedFree and low-cost kits by stateRadon Action Month checklistFlorida radon program

Are radon levels high in Hillsborough County?

In 2023, 7.5% of the radon tests reported to CDC for Hillsborough County, Florida were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.9 pCi/L. That is a share of reported tests, not of homes. EPA places Hillsborough County in Zone 2, moderate predicted potential, a predicted average indoor screening level 2 to 4 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.

Radon levels: what a result meansWhat is radon?Radon levels in Florida

Who does radon mitigation in Hillsborough County?

No listed mitigator names Hillsborough County as a service area yet; the Florida directory lists 74 companies. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether Florida requires one.

Radon mitigation: how it worksRadon mitigation costRadon mitigation systemsMitigators in Florida

What EPA radon zone is Hillsborough County in?

EPA places Hillsborough County, Florida in Zone 2, which EPA describes as moderate predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.

Should I test my home in Hillsborough County?

Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.

When is the best time of year to test?

EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.

What does it cost to test?

EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.

Which counties border Hillsborough County?

Hillsborough County borders 5 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.

If you own, buy, sell or rent

What these figures mean for each reader, with the guide that covers it

Hillsborough County in figures

The figures above, said in words

What the published data says about Hillsborough County, in words. A zone and a share of tests describe an area, never the level in any one home.

    • Predicted

      Predicted

      EPA places Hillsborough County in Zone 2, moderate predicted potential, as it does 8 other counties of Florida's 67.

      Of the 5 bordering counties, EPA places Polk County in Zone 2 and Hardee County, Manatee County, Pasco County and Pinellas County in Zone 3.

  • Reported tests

    Measured

    CDC has annual figures for Hillsborough County for 10 years, 2014 to 2023. In 2023, 7.5% of 984 reported tests were at or above 4 pCi/L.

    Across those years the share ranged from 4.8% (2021) to 17.6% (2022). Few tests in a year can move it a long way.

  • Local record

    Florida's radon program is the Florida’s Radon Program, run by Florida Department of Health; its contacts are under Local resources.

    The county's largest incorporated places are Tampa, Plant City and Temple Terrace; the figures here cover them as part of the county.

Products

Hillsborough County, Products

Testing and mitigation products

Whatever the figures for Hillsborough County show, only a test tells you about one home.

Test kits and monitors42

See all products

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Best radon monitors for Hillsborough County homes, compared

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Hillsborough County, Bordering counties

Counties bordering Hillsborough County

Calculated by Radon411
Why bordering counties matter

5 counties share a boundary with Hillsborough County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.

Hillsborough County, Cities and towns

Cities and towns in Hillsborough County

The radon figures on this page are for Hillsborough County as a whole. They do not differ by city or town.

  • Plant City
  • Temple Terrace

3 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.

Hillsborough County, Next steps

What to do next

Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.