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New Hampshire Radon Map and Levels by County

New Hampshire's counties span EPA Zones 1 and 2. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

Predicted
1 of 10counties in Zone 1, EPA's highest radon zone
Measured
By countyCDC publishes New Hampshire's test figures by county: 10 of 10 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 Hampshire, At a glance

New Hampshire at a glance

Predicted: EPA radon zone

10 of 10 counties classified

EPA classifies counties, not states. Of the 10 counties in New Hampshire with a zone, 1 is in Zone 1 and 9 in Zone 2.

  • Zone 1: Highest predicted potentialgreater than 4 pCi/L1 of 10 counties · 10.0%
  • Zone 2: Moderate predicted potential2 to 4 pCi/L9 of 10 counties · 90.0%

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 Hampshire's radon test figures by county: 10 of its 10 counties have one. Each one's share is in the county list.

New Hampshire, Counties

New Hampshire counties by EPA zone

Predicted

New Hampshire's radon map, then all 10 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 Hampshire radon map by county: EPA radon zones. Map of New Hampshire's 10 counties shaded by EPA radon zone: Zone 1 in red-orange, Zone 2 in amber. 1 in Zone 1, 9 in Zone 2, 0 in Zone 3.
New Hampshire radon map by countyEPA radon zones for New Hampshire's counties: 1 county in Zone 1, 9 counties in Zone 2, 0 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.

Local help

New Hampshire, Local resources

Local resources in New Hampshire

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

What New Hampshire's program says
Licensing of radon professionals
There is no requirement in New Hampshire for those professionals testing for radon to be certified but it is recommended to use a nationally certified radon measurement professional especially if a real estate transaction is involved.

Radon Action Brief

National Radon Action MonthPre-sale

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

Area data, not a test of the building.

What it means

New Hampshire, Questions

Questions about radon in New Hampshire

Common questions

9 questions, answered from the figures above

Is radon a problem in New Hampshire?

EPA's Map of Radon Zones places 1 of the 10 New Hampshire counties it classifies in Zone 1, the highest predicted potential, 9 in Zone 2 and 0 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 Hampshire on the radon mapRadon levels by state

Who does radon mitigation in New Hampshire?

Radon411 has no radon business listed for New Hampshire yet. 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 Hampshire

How do I get a radon test in New Hampshire?

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 Hampshire 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 Hampshire radon program

Which New Hampshire counties are in EPA radon Zone 1?

1 county is in Zone 1: Carroll 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 Carroll County

Which New Hampshire counties have the highest radon?

10 of New Hampshire's 10 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 Hampshire are high?

CDC has published no statewide radon testing statistics for New Hampshire, 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 Hampshire in?

New Hampshire is in EPA Region 1: New England.

Do I need to test my home in New Hampshire?

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 Hampshire?

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 Hampshire. They are predictions for areas, and none of them measures your building.

New Hampshire in figures

The figures above, said in words

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

    • Predicted

      Predicted

      EPA places 1 of New Hampshire's 10 counties in Zone 1 and 9 in Zone 2.

      The Zone 1 county: Carroll County.

    • Compared

      Calculated by Radon411

      10% of New Hampshire'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 Hampshire on file here.

    10 of the 10 counties have a published county figure; the most tests in each one's latest year were reported for Rockingham County (638 tests in 2021), Hillsborough County (610 tests in 2021) and Strafford County (213 tests in 2021).

  • Local record

    New Hampshire's radon program is the New Hampshire Radon Program, run by New Hampshire Department of Health and Human Services; its contacts are under Local resources.

    One city has a page setting the figures of the counties it lies in side by side: Manchester.

Products

New Hampshire, Products

Testing and mitigation products

Whatever the figures for New Hampshire 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 Hampshire homes, compared

Testing

5

Mitigation

3

Explore

Cities in New Hampshire 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 Hampshire, 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.