Highest Radon Risk ZIP Codes in New Hampshire

Out of 32 ZIP codes with data in New Hampshire, these are the lowest-ranked areas for radon zone. See also: National ZIP Codes with Highest Radon Risk | All New Hampshire Rankings

Statistic	Value
ZIP codes ranked	32
Lowest value	Zone 1 (High)
Median value	Zone 1 (High)
State	New Hampshire

32 Lowest-Ranked ZIP Codes

Rank	ZIP Code	City	State	Radon Zone	Safety Score
1	03849	Madison	NH	Zone 1 (High)	12/100
2	03838	Glen	NH	Zone 1 (High)	15/100
3	03816	Center Tuftonboro	NH	Zone 1 (High)	31/100
4	03814	Center Ossipee	NH	Zone 1 (High)	34/100
5	03864	Ossipee	NH	Zone 1 (High)	38/100
6	03227	Center Sandwich	NH	Zone 1 (High)	40/100
7	03259	North Sandwich	NH	Zone 1 (High)	40/100
8	03832	Eaton Center	NH	Zone 1 (High)	40/100
9	03847	Kearsarge	NH	Zone 1 (High)	40/100
10	03850	Melvin Village	NH	Zone 1 (High)	40/100
11	03852	Milton Mills	NH	Zone 1 (High)	40/100
12	03853	Mirror Lake	NH	Zone 1 (High)	40/100
13	03875	Silver Lake	NH	Zone 1 (High)	40/100
14	03896	Wolfeboro Falls	NH	Zone 1 (High)	40/100
15	03897	Wonalancet	NH	Zone 1 (High)	40/100
16	03254	Moultonborough	NH	Zone 1 (High)	41/100
17	03886	Tamworth	NH	Zone 1 (High)	43/100
18	03813	Center Conway	NH	Zone 1 (High)	45/100
19	03840	Greenland	NH	Zone 1 (High)	45/100
20	03890	West Ossipee	NH	Zone 1 (High)	45/100
21	03872	Sanbornville	NH	Zone 1 (High)	50/100
22	03882	Effingham	NH	Zone 1 (High)	51/100
23	03817	Chocorua	NH	Zone 1 (High)	53/100
24	03830	East Wakefield	NH	Zone 1 (High)	53/100
25	03883	South Tamworth	NH	Zone 1 (High)	53/100
26	03818	Conway	NH	Zone 1 (High)	59/100
27	03846	Jackson	NH	Zone 1 (High)	59/100
28	03812	Bartlett	NH	Zone 1 (High)	60/100
29	03836	Freedom	NH	Zone 1 (High)	61/100
30	03860	North Conway	NH	Zone 1 (High)	63/100
31	03845	Intervale	NH	Zone 1 (High)	69/100
32	03894	Wolfeboro	NH	Zone 1 (High)	69/100

Methodology

Radon rankings are based on EPA county-level radon zone classifications. Zone 1 (highest risk) has predicted average indoor radon levels above 4 pCi/L — the EPA action level. Zone 2 is moderate (2-4 pCi/L) and Zone 3 is low (below 2 pCi/L). Within Zone 1, ZIP codes are sub-ranked by Home Safety Score to prioritize areas with compounding risk factors.

Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-06-04.

Frequently Asked Questions

What is EPA Radon Zone 1?

Zone 1 is the EPA highest-risk classification, meaning the county has predicted average indoor radon levels above 4 pCi/L — the level at which the EPA recommends mitigation. Radon causes about 21,000 lung cancer deaths per year in the U.S.

Should I test for radon?

The EPA recommends testing all homes regardless of radon zone. A DIY test kit costs $15-40. Professional testing costs $150-250. If levels exceed 4 pCi/L, mitigation systems ($800-2,500) can reduce radon by up to 99%.

Highest Radon Risk ZIP Codes in New Hampshire — 2026

32 Lowest-Ranked ZIP Codes

Methodology

Frequently Asked Questions

What is EPA Radon Zone 1?

Should I test for radon?

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