Data report · 2026

Michigan Water Damage Risk Index

Where in Michigan is a house most likely to take on water? We combined Census housing age with ten years of daily weather for 83 of Michigan's 83 counties to rank them.

Highest index

Gogebic

Score 75 of 100

Most pipe-freeze nights

Iron

111 nights ≤ 20°F a year

Oldest housing

Wayne

59% built before 1960

Most heavy-rain days

Cass

6 days ≥ 1 inch a year

< 3838–4646–5454–61≥ 61 index (0–100)

Key findings

The five highest-scoring counties are Gogebic, Iron, Calhoun, Wayne, Ontonagon. Each combines old housing with harsher-than-average winters or frequent downpours.
Wayne County has the oldest housing in the state, with 59% of homes built before 1960, against a county median of 32%.
Iron County averaged 111 nights a year at 20°F or colder, the most of any county in the data. The county median is 54.
Grand Traverse County has the newest housing, with 31% 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	Gogebic	75	107	57%	4.2	1
2	Iron	72	111	49%	4	1
3	Calhoun	69	41	49%	5.7	22
4	Wayne	69	35	59%	5.5	35
5	Ontonagon	68	100	46%	3.7	2
6	Jackson	66	44	42%	5.5	17
7	St. Joseph	66	38	42%	5.7	25
8	Gratiot	64	46	42%	4.4	19
9	Ionia	64	46	41%	5	17
10	Hillsdale	63	43	41%	5.6	17
11	Lenawee	63	40	43%	5	21
12	Shiawassee	63	44	41%	4.8	22
13	Berrien	62	35	41%	5.4	30
14	Branch	62	41	39%	5.9	20
15	Baraga	61	102	35%	3.8	1
16	Delta	61	85	41%	3.6	2
17	Houghton	61	94	50%	2.6	2
18	Schoolcraft	61	85	34%	4.4	2
19	Cass	60	38	34%	6	25
20	Dickinson	60	100	41%	3.4	1
21	Ingham	59	44	36%	5	20
22	Keweenaw	59	91	50%	2.5	1
23	Marquette	59	101	38%	3.7	0
24	Saginaw	58	44	38%	4.5	22
25	Genesee	57	45	36%	4	23
26	Montcalm	57	52	30%	5.1	11
27	Barry	56	43	33%	5.7	20
28	Kalamazoo	56	38	32%	6	26
29	Kent	56	47	33%	4.8	15
30	Menominee	56	85	41%	2.8	2
31	Muskegon	56	43	41%	4.8	14
32	Bay	55	43	47%	3.6	23
33	Alger	54	89	32%	3.8	1
34	Manistee	54	56	34%	4	8
35	Van Buren	53	35	33%	5.4	24
36	Wexford	53	67	28%	4.2	5
37	Mason	51	52	33%	4	8
38	Monroe	51	34	34%	4.6	34
39	Oakland	51	44	28%	4.5	24
40	Oceana	51	49	30%	4.6	8
41	Allegan	50	39	28%	5.3	21
42	Chippewa	50	84	34%	3.1	2
43	Huron	50	46	42%	2.8	15
44	Clinton	49	44	26%	4.6	22
45	Mackinac	48	80	31%	3.3	3
46	Tuscola	48	45	39%	3.4	18
47	Washtenaw	48	46	25%	4.9	19
48	Alpena	47	65	39%	1.9	5
49	Eaton	47	43	26%	5.2	20
50	Antrim	46	62	24%	4.1	8
51	Newaygo	46	55	28%	3.9	6
52	Osceola	46	66	27%	3.7	4
53	St. Clair	46	36	35%	3.7	33
54	Lake	44	60	26%	4	6
55	Luce	44	90	26%	3.1	2
56	Mecosta	44	58	24%	4.2	6
57	Ogemaw	44	64	26%	3.7	7
58	Macomb	43	34	25%	5.2	37
59	Sanilac	43	43	40%	2.9	20
60	Arenac	42	51	26%	3.7	15
61	Iosco	42	57	29%	3.2	9
62	Isabella	42	52	21%	4.5	11
63	Midland	42	46	26%	3.7	19
64	Presque Isle	42	68	33%	1.8	4
65	Grand Traverse	39	59	19%	3.9	8
66	Charlevoix	38	62	23%	3.6	8
67	Kalkaska	38	68	17%	3.7	5
68	Montmorency	38	71	26%	1.8	4
69	Benzie	37	57	23%	3.6	10
70	Lapeer	37	45	26%	3.3	21
71	Livingston	37	48	14%	4	20
72	Gladwin	36	54	23%	3.5	13
73	Clare	35	61	22%	3.4	7
74	Emmet	35	65	23%	2.9	6
75	Ottawa	35	40	19%	4.8	18
76	Alcona	34	64	26%	2.1	6
77	Cheboygan	34	70	23%	2.6	4
78	Leelanau	34	54	16%	3.7	12
79	Missaukee	33	68	20%	3	4
80	Otsego	32	74	15%	3	4
81	Roscommon	32	65	18%	3.2	5
82	Crawford	31	71	17%	2.7	4
83	Oscoda	30	70	22%	1.5	4

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 Michigan 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, "Michigan Water Damage Risk Index 2026," https://localwatermold.com/michigan/michigan-water-damage-risk/. Data: U.S. Census Bureau ACS 2020-2024; NOAA nClimGrid-Daily 2015–2024.