Data report · 2026

New York Water Damage Risk Index

Where in New York is a house most likely to take on water? We combined Census housing age with ten years of daily weather for 57 of New York's 57 counties to rank them.

Highest index

Fulton

Score 79 of 100

Most pipe-freeze nights

Hamilton

91 nights ≤ 20°F a year

Oldest housing

Nassau

66% built before 1960

Most heavy-rain days

Ulster

10.8 days ≥ 1 inch a year

< 4141–4747–5353–57≥ 57 index (0–100)

Key findings

The five highest-scoring counties are Fulton, Herkimer, Schenectady, Otsego, Montgomery. Each combines old housing with harsher-than-average winters or frequent downpours.
Nassau County has the oldest housing in the state, with 66% of homes built before 1960, against a county median of 45%.
Hamilton County averaged 91 nights a year at 20°F or colder, the most of any county in the data. The county median is 55.
Saratoga County has the newest housing, with 29% of homes built since 2000, which pulls its index down even where winters are cold.

Weather: NOAA nClimGrid-Daily county averages, 2015–2024. Housing: ACS 2020-2024.

All counties

Select a column header to sort.

Rank	County	Index	Freeze nights	Pre-1960 homes	Heavy-rain days	Muggy nights
1	Fulton	79	69	56%	9	5
2	Herkimer	76	82	55%	7.6	3
3	Schenectady	72	56	57%	6.8	16
4	Otsego	71	67	54%	7.4	4
5	Montgomery	70	60	65%	6.5	11
6	Oneida	70	65	54%	7.3	8
7	Nassau	68	15	66%	8.7	66
8	Broome	60	55	52%	6.8	9
9	Ulster	59	50	45%	10.8	14
10	Westchester	59	28	52%	8.4	48
11	Hamilton	58	91	39%	8.1	1
12	Cortland	57	62	49%	5.3	7
13	Washington	57	64	48%	5	10
14	Chemung	56	52	58%	5	10
15	Essex	56	88	43%	6.5	2
16	Franklin	56	88	46%	4.9	3
17	Madison	56	64	46%	5.3	8
18	Albany	55	53	46%	7.3	15
19	Chautauqua	55	49	59%	4.9	13
20	St. Lawrence	55	80	47%	4.5	7
21	Chenango	54	62	44%	6.6	6
22	Rensselaer	54	54	48%	5.8	15
23	Greene	53	60	38%	8.9	6
24	Warren	53	76	38%	7.6	4
25	Wyoming	53	56	50%	4.9	11
26	Cattaraugus	52	58	50%	5	5
27	Delaware	52	65	40%	7.7	2
28	Jefferson	52	67	42%	4.8	15
29	Lewis	52	81	42%	6.1	4
30	Cayuga	49	49	52%	4.5	16
31	Erie	49	47	55%	4.2	17
32	Columbia	48	48	44%	6.5	21
33	Oswego	48	56	40%	6	16
34	Saratoga	47	61	23%	7.5	13
35	Sullivan	47	54	37%	9.6	8
36	Genesee	46	48	54%	3.8	18
37	Onondaga	45	52	45%	4.6	16
38	Clinton	44	80	37%	4.5	11
39	Orleans	44	44	54%	3.4	26
40	Schoharie	44	66	38%	6.4	3
41	Steuben	43	56	47%	4.1	6
42	Seneca	42	46	51%	3.9	18
43	Tioga	42	54	40%	6.5	10
44	Allegany	41	59	45%	4.1	6
45	Niagara	41	42	54%	3.1	30
46	Putnam	41	38	37%	7.9	36
47	Orange	40	40	35%	8.5	29
48	Rockland	40	30	28%	9.5	46
49	Suffolk	37	18	31%	8	51
50	Dutchess	35	42	35%	6.7	29
51	Schuyler	35	53	41%	4.3	12
52	Tompkins	33	55	36%	4.6	11
53	Monroe	32	43	43%	3.9	25
54	Yates	32	49	42%	3.5	15
55	Wayne	31	46	44%	3	21
56	Livingston	29	48	42%	3.4	15
57	Ontario	24	48	35%	3.8	17

Methodology

For each county with weather data, we convert four factors to a percentile rank among those counties (0 = lowest, 100 = highest), then take a weighted average:

Pipe-freeze nights (nights ≤ 20°F / yr), weight 30%
Homes built before 1960 (% of homes), weight 30%
Heavy-rain days (days ≥ 1 in / yr), weight 25%
Muggy nights (nights ≥ 65°F / yr), weight 15%

Freezing weather and old plumbing get the most weight because burst and failing supply lines are among the most common causes of household water damage. Heavy rain drives basement flooding and sewer backups, and warm, muggy nights mark the humid air that lets mold follow. The index is relative: a low score means lower risk than other New York counties, not no risk.

Limits: weather values are county-wide averages, so hollows, ridges and lakeshores can differ; ACS housing figures are survey estimates; the index doesn't account for floodplains, soil, or local sewer systems. Full details on our data sources page.

Cite this data

You're welcome to use these figures with attribution. Suggested citation:

Local Water & Mold, "New York Water Damage Risk Index 2026," https://localwatermold.com/new-york/new-york-water-damage-risk/. Data: U.S. Census Bureau ACS 2020-2024; NOAA nClimGrid-Daily 2015–2024.