Radon in New York: radon map by county

EPA's Map of Radon Zones puts 34 of New York's 62 counties in Zone 1 (predicted average indoor radon above 4 pCi/L), 13 in Zone 2 and 15 in Zone 3. Of 65,893 building tests that radon laboratories reported for 2008 to 2017, 24.2% were at or above EPA's 4 pCi/L action level, against 36.5% nationally (number 29 of 42 states with 1,000+ tests). The highest county share is Chemung County (52.3% of 1,269 tests).

counties in Zone 1 (above 4 pCi/L predicted)

counties in Zone 2 (2 to 4)

counties in Zone 3 (below 2)

24.2%

of 65,893 lab tests at or above 4 pCi/L

Radon by county in New York

EPA radon zone and radon test results for each county in New York
County	EPA zone	Lab tests	Median	4+ pCi/L	NY agency data
Albany County	Zone 1	1,566	1.4	15.7%	24.4% of 3,161 basement kits
Allegany County	Zone 1	217	2.9	42.6%	55.2% of 551 basement kits
Bronx County	Zone 3	132	0.5	3.2%	n/a
Broome County	Zone 1	3,006	1.8	24.9%	37.3% of 3,458 basement kits
Cattaraugus County	Zone 1	525	3.0	40.6%	50.4% of 1,506 basement kits
Cayuga County	Zone 1	542	2.1	27.8%	33% of 1,383 basement kits
Chautauqua County	Zone 1	855	2.5	38%	35.9% of 1,136 basement kits
Chemung County	Zone 1	1,269	4.3	52.3%	70.2% of 2,128 basement kits
Chenango County	Zone 1	490	2.6	33.4%	55.6% of 727 basement kits
Clinton County	Zone 2	65	1.4	8%	12.2% of 377 basement kits
Columbia County	Zone 1	379	2.7	39.8%	50.1% of 801 basement kits
Cortland County	Zone 1	545	4.1	51%	74.4% of 2,084 basement kits
Delaware County	Zone 1	498	1.8	27.6%	51.5% of 767 basement kits
Dutchess County	Zone 1	1,394	3.0	40.8%	53.3% of 3,428 basement kits
Erie County	Zone 1	11,506	1.5	18.2%	22.3% of 7,957 basement kits
Essex County	Zone 3	93	1.3	10.5%	6.1% of 180 basement kits
Franklin County	Zone 3	19	1.0	21.9%	4.9% of 123 basement kits
Fulton County	Zone 3	190	1.2	11.7%	15.3% of 170 basement kits
Genesee County	Zone 1	288	2.6	34.7%	37.2% of 1,076 basement kits
Greene County	Zone 1	302	2.0	27.6%	38.9% of 391 basement kits
Hamilton County	Zone 3	9	1.5	27.3%	16% of 25 basement kits
Herkimer County	Zone 3	255	3.1	41.5%	45.9% of 331 basement kits
Jefferson County	Zone 2	609	1.5	16%	28.7% of 477 basement kits
Kings County	Zone 3	489	0.7	8.1%	n/a
Lewis County	Zone 2	62	1.4	20.2%	31.2% of 125 basement kits
Livingston County	Zone 1	383	3.1	38.3%	43.4% of 1,038 basement kits
Madison County	Zone 1	640	2.6	34.6%	40.9% of 1,308 basement kits
Monroe County	Zone 2	6,356	1.8	15.1%	16.4% of 3,356 basement kits
Montgomery County	Zone 2	157	1.6	14.7%	32.5% of 274 basement kits
Nassau County	Zone 3	483	1.0	5.2%	5.7% of 837 basement kits
New York County	Zone 3	498	0.2	7.1%	7.2% of 1,611 basement kits
Niagara County	Zone 2	1,731	1.6	14.3%	9.9% of 1,639 basement kits
Oneida County	Zone 2	1,458	2.5	34.6%	38.9% of 2,351 basement kits
Onondaga County	Zone 1	5,324	2.0	28.4%	46% of 10,354 basement kits
Ontario County	Zone 1	1,206	2.6	32.8%	36.5% of 769 basement kits
Orange County	Zone 1	1,715	2.2	30.6%	38.8% of 2,558 basement kits
Orleans County	Zone 2	122	2.0	24.5%	20.9% of 532 basement kits
Oswego County	Zone 2	452	1.4	15.2%	15.2% of 316 basement kits
Otsego County	Zone 1	671	2.8	37.6%	56.5% of 1,603 basement kits
Putnam County	Zone 1	637	1.9	24.7%	34.3% of 1,261 basement kits
Queens County	Zone 3	320	0.8	5.3%	n/a
Rensselaer County	Zone 1	899	2.1	29.5%	44.8% of 2,540 basement kits
Richmond County	Zone 3	231	1.0	11.7%	n/a
Rockland County	Zone 3	641	1.5	14.6%	14.7% of 3,004 basement kits
Saratoga County	Zone 2	2,598	2.0	22.3%	27.8% of 1,849 basement kits
Schenectady County	Zone 2	1,137	1.7	17.3%	22.8% of 1,382 basement kits
Schoharie County	Zone 1	244	1.7	21.8%	40.2% of 386 basement kits
Schuyler County	Zone 1	186	2.5	38.6%	42.7% of 260 basement kits
Seneca County	Zone 1	260	2.0	21.3%	19.1% of 225 basement kits
St. Lawrence County	Zone 2	121	1.2	13.2%	13.9% of 368 basement kits
Steuben County	Zone 1	805	3.4	45.3%	65.3% of 1,638 basement kits
Suffolk County	Zone 3	397	1.1	8%	7.6% of 580 basement kits
Sullivan County	Zone 1	160	1.3	19.8%	27.5% of 247 basement kits
Tioga County	Zone 1	777	2.7	38.9%	57% of 1,061 basement kits
Tompkins County	Zone 1	2,417	2.3	28%	38.3% of 2,152 basement kits
Ulster County	Zone 1	1,804	2.2	29.8%	36.3% of 1,520 basement kits
Warren County	Zone 3	1,466	1.6	15.7%	18% of 338 basement kits
Washington County	Zone 1	896	2.0	25.6%	42.2% of 618 basement kits
Wayne County	Zone 2	669	2.0	26.9%	28.3% of 643 basement kits
Westchester County	Zone 3	2,339	1.5	16.3%	17.5% of 2,875 basement kits
Wyoming County	Zone 1	288	3.0	39.3%	52% of 567 basement kits
Yates County	Zone 1	100	3.5	45.9%	41.2% of 255 basement kits

Lab tests: buildings tested by radon laboratories, 2008 to 2017; median in pCi/L; “4+ pCi/L” is the share of tests at or above EPA's action level. n/a: no value on file (no tests, or too few to report).

New York state radon data

The state health department reports short-term charcoal kit tests provided through the state radon program since 1987, by county and town, basement and first floor. The county pages show these results next to the laboratory results. New York county pages also list the towns with results.

What the zones mean

Zone 1 counties have a predicted average indoor radon screening level above 4 pCi/L, Zone 2 from 2 to 4 pCi/L and Zone 3 below 2 pCi/L. The prediction is from 1993 indoor measurements, geology, aerial radioactivity, soils and foundation types. EPA: “This map should not be used to determine if individual homes need to be tested.” EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, because there is no known safe level of exposure.

Buying in New York? Order a New York title search: owner of record, deeds, mortgages and liens in Manhattan, Brooklyn, Queens, The Bronx, Staten Island, Erie County, $49 per report.

Radon in New York: questions

What radon zone is New York?

EPA's 1993 map does not give states one zone; it zones each county. In New York, 34 counties are Zone 1, 13 Zone 2 and 15 Zone 3. EPA says the map "should not be used to determine if individual homes need to be tested".

Which New York counties have the highest radon levels?

By the share of laboratory tests at or above 4 pCi/L for 2008 to 2017 (counties with 20 or more tests): Chemung County 52.3% (median 4.3 pCi/L, 1,269 tests); Cortland County 51% (median 4.1 pCi/L, 545 tests); Yates County 45.9% (median 3.5 pCi/L, 100 tests); Steuben County 45.3% (median 3.4 pCi/L, 805 tests); Allegany County 42.6% (median 2.9 pCi/L, 217 tests).

How common is high radon in New York?

24.2% of the 65,893 tests in the laboratory data for New York (2008 to 2017) were at or above 4 pCi/L; the national share was 36.5%. Buildings are tested by choice, often because of a sale or a concern, so the share describes the tests on file, not every home.

Does New York publish its own radon test data?

Yes. The state health department reports short-term charcoal kit tests provided through the state radon program since 1987, by county and town, basement and first floor. Each New York county page here shows those results beside the laboratory results.

Should I test for radon in New York?

Yes. EPA recommends testing every home no matter where it is, fixing it at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, because there is no known safe level of radon exposure.

States bordering New York

Radon in Connecticut (3 of 9 in Zone 1)Radon in Massachusetts (3 of 14 in Zone 1)Radon in New Jersey (7 of 21 in Zone 1)Radon in Pennsylvania (49 of 67 in Zone 1)Radon in Vermont (0 of 14 in Zone 1)

Other free hazard lookups

All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).

Superfund sites in New York · Radon map of every state

Data compiled 2026-10-20. County-level screening information, not a radon measurement of any building.