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New Jersey Radon Map and Levels by County

New Jersey's counties span all three EPA radon zones. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

Predicted
7 of 21counties in Zone 1, EPA's highest radon zone
Measured
By countyCDC publishes New Jersey's test figures by county: 21 of 21 counties have one.
Your home
Test to knowNo area figure here is a reading of your home.
How to test this homeFind a certified tester

The data

New Jersey, At a glance

New Jersey at a glance

Predicted: EPA radon zone

21 of 21 counties classified

EPA classifies counties, not states. Of the 21 counties in New Jersey with a zone, 7 are in Zone 1, 11 in Zone 2 and 3 in Zone 3.

  • Zone 1: Highest predicted potentialgreater than 4 pCi/L7 of 21 counties · 33.3%
  • Zone 2: Moderate predicted potential2 to 4 pCi/L11 of 21 counties · 52.4%
  • Zone 3: Lower predicted potentialless than 2 pCi/L3 of 21 counties · 14.3%

An EPA radon zone describes predicted potential across a whole county. It is not intended to determine whether any individual home should be tested, and homes with elevated levels occur in all three zones. EPA recommends testing every home regardless of zone, and testing is the only way to know the radon level in a specific building.

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

CDC test figures, county by county

CDC publishes New Jersey's radon test figures by county: 21 of its 21 counties have one. Each one's share is in the county list.

New Jersey, Counties

New Jersey counties by EPA zone

Predicted

New Jersey's radon map, then all 21 counties by the zone EPA predicts for each, highest reported share of tests at or above 4 pCi/L first. Each has its own report.

New Jersey radon map by county: EPA radon zones. Map of New Jersey's 21 counties shaded by EPA radon zone: Zone 1 in red-orange, Zone 2 in amber, Zone 3 in pale sand. 7 in Zone 1, 11 in Zone 2, 3 in Zone 3.
New Jersey radon map by countyEPA radon zones for New Jersey's counties: 7 counties in Zone 1, 11 counties in Zone 2, 3 counties in Zone 3.Predicted potential for each county, not a reading of any home. Homes with elevated levels of radon have been found in all three zones.

Zone 1: highest predicted potential7

Local help

New Jersey, Local resources

Local resources in New Jersey

Who to ask in New Jersey: its radon program, test kits and professionals.

What New Jersey's program says
Phone
800-648-0394
Licensing of radon professionals
By law, all businesses and professionals conducting radon testing and mitigation in New Jersey must be certified by the DEP.
Disclosure when a home is sold or rented
Under the law, the seller must provide the buyer, at the time the contract of sale is entered into, with a copy of the results of the radon test and evidence of any mitigation or treatment.

Radon Action Brief

National Radon Action MonthPre-sale

The radon brief for your New Jersey county, 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 your New Jersey county's BriefSee a free sample

Area data, not a test of the building.

What it means

New Jersey, Questions

Questions about radon in New Jersey

Common questions

9 questions, answered from the figures above

Is radon a problem in New Jersey?

EPA's Map of Radon Zones places 7 of the 21 New Jersey counties it classifies in Zone 1, the highest predicted potential, 11 in Zone 2 and 3 in Zone 3. An EPA radon zone describes predicted potential across a whole county. It is not intended to determine whether any individual home should be tested, and homes with elevated levels occur in all three zones. EPA recommends testing every home regardless of zone, and testing is the only way to know the radon level in a specific building.

New Jersey on the radon mapRadon levels by state

Who does radon mitigation in New Jersey?

Radon411's New Jersey directory lists 15 radon businesses for testing, mitigation or both, each with the licensing list it was read from. 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.

How radon mitigation worksWhat mitigation costsRadon professionals in New Jersey

How do I get a radon test in New Jersey?

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. The New Jersey radon program is the place to ask about certified testers and any test kit offer it runs.

How to test a homeFree and low-cost kits by stateNew Jersey radon program

Which New Jersey counties are in EPA radon Zone 1?

7 counties are in Zone 1: Hunterdon County, Mercer County, Monmouth County, Morris County, Somerset County, Sussex County, Warren County. Zone 1 is EPA's class for highest predicted potential, a predicted average indoor screening level greater than 4 pCi/L. A zone is a prediction for a county, not a measurement of any home.

Radon in Hunterdon CountyRadon in Mercer CountyRadon in Monmouth County

Which New Jersey counties have the highest radon?

21 of New Jersey's 21 counties have an EPA radon zone published here. Radon411 will not rank counties on data it does not hold, and a zone is a prediction for an area rather than a measurement of any building.

What share of radon tests in New Jersey are high?

CDC has published no statewide radon testing statistics for New Jersey, so we cannot give a figure. Where CDC does publish one, the percentage describes radon tests reported to CDC, not homes.

Which EPA region is New Jersey in?

New Jersey is in EPA Region 2: New Jersey, New York, Puerto Rico, U.S. Virgin Islands.

Do I need to test my home in New Jersey?

Yes, wherever you live in the state. 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.

Why does this page show coverage rather than one radon level for New Jersey?

A statewide figure averages counties with very different geology and very different numbers of reported tests, so it hides more than it shows. The county report is the level at which the EPA zone, the geologic potential and the reported testing statistics are actually published, which is why the county table above links to every one of them.

If you own, buy, sell or rent

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

The zone counts on this page describe counties across New Jersey. They are predictions for areas, and none of them measures your building.

New Jersey in figures

The figures above, said in words

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

    • Predicted

      Predicted

      EPA places 7 of New Jersey's 21 counties in Zone 1, 11 in Zone 2 and 3 in Zone 3.

      Zone 1 counties, A to Z, begin with Hunterdon County, Mercer County and Monmouth County; the county section below lists all 7.

    • Compared

      Calculated by Radon411

      33% of New Jersey's counties with a zone on file are in Zone 1, a smaller share than across all U.S. counties (34%). It is a share of counties, not of land, people or homes.

  • Reported tests

    Measured

    CDC has no statewide testing figure for New Jersey on file here.

    21 of the 21 counties have a published county figure; the most tests in each one's latest year were reported for Bergen County (11,440 tests in 2022), Morris County (10,939 tests in 2022) and Monmouth County (9,745 tests in 2022).

  • Local record

    New Jersey's radon program is the Radon Section, run by New Jersey Department of Environmental Protection; its contacts are under Local resources.

    2 cities have a page setting the figures of the counties it lies in side by side: Freehold and Trenton.

Products

New Jersey, Products

Testing and mitigation products

Whatever the figures for New Jersey show, only a test tells you about one home.

Test kits and monitors42

See all products

As an Amazon Associate, Radon411 earns from qualifying purchases.

Best radon monitors for New Jersey homes, compared

Testing

5

Mitigation

3

Explore

Cities in New Jersey with their own page

Radon data is published by county, not by city. Each city page sets the figures of the counties the city lies in side by side.

New Jersey, Next steps

What to do next

  1. LearnKnow what radon isWhat radon is, how it gets indoors, and why a county zone is not a reading for your home.Learn about radon
  2. TestTest the building you live inShort-term or long-term, where the device goes, and closed-house conditions.How to test
  3. FixBring a high level downHow a mitigation system works, and the retest that confirms it.How mitigation works
  4. Find a proHire a certified professionalMeasurement and mitigation professionals by state, with their certifications.Find a professional

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.