42%tests ≥ 4 pCi/L
4,077tests on record
3.1median pCi/L
Zone 2EPA zone (1993 prediction)

Test results in Rockingham County

ResultShareEPA guidance
Below 2 pCi/L35%Below EPA's levels
2 to 4 pCi/L23%Consider fixing
4 pCi/L or more42%EPA recommends fixing

What the data shows

Where Rockingham County sits among New Hampshire's 10 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017
0%10%20%30%40%50%

How Rockingham County compares

Rockingham County ranks 3 of 6 among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
York County, Maine48%Strafford County43%Rockingham County42%Hillsborough County34%Merrimack County31%Essex County, Massachuset…29%New Hampshire 35%
Data table
AreaTests ≥ 4 pCi/LTests
York County, Maine48%1,389
Strafford County43%870
Rockingham County42%4,077
Hillsborough County34%5,528
Merrimack County31%1,179
Essex County, Massachusetts29%20,398
New Hampshire (10 counties)35%15,608

Same source as Rockingham County.

What it means for your home

About 1 in 2 results in Rockingham County were at or above 4 pCi/L, where the EPA recommends a fix. Only a test shows your own home's level.

Levels in pCi/L from the EPA. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.

Test your home

Start with a short-term test (2–90 days) and confirm a result of 4 pCi/L or more with a second test. EPA guide

Sponsored: we earn a commission on purchases through these links. We haven't tested Airthings monitors yet.

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Fixing high radon

No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →

About this data

Source: Radon test results from laboratories (CDC Environmental Public Health Tracking Network). Period: 2008–2017. Tests: 4,077. Read the methodology →

These are voluntary and real-estate tests, not a random sample of homes, so they describe tested homes rather than every home.

About this page

Published by Ray Roman, editor of Radon by County. Figures are loaded from the cited source and spot-checked against it. Editorial policy · About us