Is radon high in Trenton, New Jersey?

Low. Averaging the model's ZIP-code predictions across Trenton (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 1.2 pCi/L - about 34% below the US average of 1.8 and close to the New Jersey average of 1.3. That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Trenton ranks 5 of 22 New Jersey cities on this site.

Which Trenton ZIP codes have the highest radon?

Predictions for the 8 modeled ZIP codes in Trenton range from 0.8 to 1.7 pCi/L in the basement. 0% of them are predicted at or above 4 pCi/L and 0% at or above 2. The city is fairly uniform, so the city-wide number is a reasonable guide for any neighborhood.

Should I test for radon in Trenton?

Yes, once. The EPA recommends testing every home regardless of area. A short-term kit costs little and settles the question for your house; Trenton's low predicted average describes the typical home, not yours.

What does EPA Radon Zone 1 mean for Trenton?

Trenton sits mainly in Mercer County, which the EPA classifies as Zone 1 - highest potential (predicted average > 4 pCi/L). The zone map dates from 1993 and covers whole counties. The newer model's city average of 1.2 pCi/L does not line up with Zone 1, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.

Radon levels in Trenton, New Jersey

LowEPA Zone 1

Predicted long-term basement average of 1.2 pCi/L (model estimate) across the 8 modeled ZIP codes in Trenton - about 34% below the US average of 1.8, close to the New Jersey average of 1.3. Ranked #5 of 22 New Jersey cities on this site. Most of the city lies in Mercer County.

Test Trenton, NJ once anyway - radon varies house to house

The predicted basement average here is 1.2 pCi/L, below the EPA's 2 pCi/L "consider fixing" threshold. That's good news for the area - but the EPA still recommends every home be tested, because foundation cracks, soil pockets and ventilation make one house very different from its neighbor. One inexpensive kit settles it.

Get a short-term test kit →Or track it with a continuous monitor

We may earn a commission from Amazon at no extra cost to you.

Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.

1.2 ± 0.06

pCi/L predicted basement mean (model SD)

0.8 ± 0.07

pCi/L predicted upstairs (above-ground) mean

0.8-1.7

range of ZIP-level basement predictions in the city

of Trenton ZIPs predicted ≥ 4 pCi/L (0% ≥ 2)

What this means for Trenton

The typical Trenton home is predicted below 2 pCi/L, the lowest band. That describes the average house; the ZIP-level predictions inside the city still span 0.8 to 1.7 pCi/L.

The city figure is not a separate estimate: it is the mean of the model's ZIP-code predictions, weighted by the share of the city's land in each ZIP (Census 2020 ZCTA-to-place relationship file). Note that the EPA classifies Mercer County as Zone 1 while the newer model predicts 1.2 pCi/L for Trenton; where they disagree, we grade on the model but show both.

Comparable New Jersey cities: Toms River (1.2), Sayreville (1.2), Lakewood (1.1), Hackensack (1.1).

ZIP codes in Trenton

ZIPs that overlap the city, largest share of its land first. Predicted basement and upstairs means are model estimates; ZIPs the model does not cover show a dash.

ZIP	Share of city	Basement	Upstairs	Grade
08618	36%	1.5 ± 0.06	1.0	Low
08611	24%	0.8 ± 0.07	0.6	Low
08638	16%	1.5 ± 0.06	1.1	Low
08609	11%	0.9 ± 0.07	0.6	Low
08629	5%	0.8 ± 0.08	0.6	Low
08608	4%	0.9 ± 0.07	0.6	Low
08610	3%	1.0 ± 0.07	0.7	Low
08628	2%	1.7 ± 0.05	1.3	Low

Testing help in New Jersey

New Jersey's radon program page is at www.nj.gov; it lists testing and certified-mitigator guidance. EPA state radon contacts page. If a test comes back at 4 pCi/L or higher, mitigation typically costs $800-$2,500 installed; use EPA find-a-professional and read the mitigation guide.

Trenton radon questions

Is radon high in Trenton, New Jersey?: Low. Averaging the model's ZIP-code predictions across Trenton (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 1.2 pCi/L - about 34% below the US average of 1.8 and close to the New Jersey average of 1.3. That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Trenton ranks 5 of 22 New Jersey cities on this site.
Which Trenton ZIP codes have the highest radon?: Predictions for the 8 modeled ZIP codes in Trenton range from 0.8 to 1.7 pCi/L in the basement. 0% of them are predicted at or above 4 pCi/L and 0% at or above 2. The city is fairly uniform, so the city-wide number is a reasonable guide for any neighborhood.
Should I test for radon in Trenton?: Yes, once. The EPA recommends testing every home regardless of area. A short-term kit costs little and settles the question for your house; Trenton's low predicted average describes the typical home, not yours.
What does EPA Radon Zone 1 mean for Trenton?: Trenton sits mainly in Mercer County, which the EPA classifies as Zone 1 - highest potential (predicted average > 4 pCi/L). The zone map dates from 1993 and covers whole counties. The newer model's city average of 1.2 pCi/L does not line up with Zone 1, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.

← All New Jersey counties and cities · Mercer County · How to test · Methodology