Data report · 2026

Tennessee Water Damage Risk Index

Where in Tennessee is a house most likely to take on water? We combined Census housing age with ten years of daily weather for 95 of Tennessee's 95 counties to rank them.

Highest index

Obion

Score 79 of 100

Most pipe-freeze nights

Johnson

23 nights ≤ 20°F a year

Oldest housing

Anderson

31% built before 1960

Most heavy-rain days

Franklin

18.4 days ≥ 1 inch a year

< 4141–4848–5555–60≥ 60 index (0–100)

Key findings

The five highest-scoring counties are Obion, Weakley, Gibson, Houston, Overton. Each combines old housing with harsher-than-average winters or frequent downpours.
Anderson County has the oldest housing in the state, with 31% of homes built before 1960, against a county median of 16%.
Johnson County averaged 23 nights a year at 20°F or colder, the most of any county in the data. The county median is 11.
Williamson County has the newest housing, with 53% 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	Obion	79	12	27%	15.2	93
2	Weakley	77	12	21%	15.6	91
3	Gibson	74	11	28%	15	91
4	Houston	70	13	21%	14	83
5	Overton	70	14	19%	15.5	57
6	Grundy	69	13	19%	17.7	49
7	Carroll	68	12	24%	13.8	87
8	Morgan	68	14	19%	15.4	47
9	Henry	66	13	19%	13.5	90
10	Smith	65	12	21%	14.6	71
11	Lincoln	64	9	23%	16.7	73
12	Cannon	63	12	18%	15.8	67
13	Van Buren	63	13	17%	15.6	58
14	Macon	62	15	14%	15.2	65
15	Dyer	61	10	27%	13.3	100
16	Franklin	61	9	20%	18.4	70
17	Shelby	61	6	27%	15	113
18	Anderson	60	10	31%	14.5	66
19	Carter	60	18	29%	8.5	8
20	Hancock	60	15	26%	11.2	43
21	Warren	60	12	17%	16	62
22	Wayne	60	9	19%	16.2	77
23	Humphreys	59	13	18%	13.2	81
24	White	59	12	16%	16.1	61
25	Coffee	58	12	16%	16.2	62
26	Hardeman	58	9	18%	15.6	94
27	Lake	58	10	26%	13.1	99
28	Stewart	58	13	11%	15	88
29	Unicoi	58	19	26%	8	8
30	Campbell	57	15	19%	13.1	42
31	Crockett	57	10	19%	13.9	96
32	Jackson	57	13	14%	15.1	66
33	Benton	56	12	19%	12.6	87
34	Haywood	56	9	19%	14.7	98
35	Johnson	56	23	20%	9	3
36	Sullivan	56	14	28%	7.3	40
37	Perry	55	10	16%	15.3	81
38	Pickett	55	15	11%	15.3	61
39	Hickman	54	12	16%	14.4	74
40	Sequatchie	54	11	14%	16.6	67
41	Cumberland	53	16	7%	16.1	40
42	Putnam	53	13	11%	16.4	60
43	Hamilton	52	7	23%	14	86
44	Lauderdale	52	8	21%	13.3	105
45	Robertson	52	14	12%	13.7	80
46	Dickson	51	14	16%	11.6	76
47	Fentress	51	16	12%	14.6	46
48	Moore	51	10	14%	16.9	73
49	Lewis	50	11	13%	15.8	70
50	Madison	50	10	16%	14.1	91
51	McNairy	50	10	15%	14.6	89
52	Trousdale	50	12	12%	14.7	75
53	Chester	49	10	17%	13.8	88
54	Lawrence	49	10	19%	14.3	70
55	Marion	49	9	14%	17.7	74
56	Maury	49	11	17%	14	72
57	Bedford	48	10	16%	14.6	75
58	McMinn	48	7	22%	13.9	80
59	Scott	48	18	11%	14.5	40
60	Clay	47	14	10%	14.5	63
61	Giles	47	10	19%	13.3	70
62	Marshall	47	11	17%	13.5	70
63	Washington	47	13	20%	6.9	41
64	DeKalb	46	12	11%	15	68
65	Bledsoe	45	11	12%	15.5	65
66	Davidson	45	10	18%	11.7	87
67	Henderson	44	11	13%	13.7	85
68	Roane	44	7	23%	13.5	74
69	Cheatham	43	13	10%	12.6	83
70	Montgomery	43	13	8%	12.8	85
71	Decatur	42	9	15%	14.3	85
72	Hardin	42	9	12%	15.2	86
73	Claiborne	41	17	14%	11.1	39
74	Greene	41	11	20%	7.9	57
75	Knox	41	8	20%	12.1	79
76	Wilson	41	11	7%	14.7	79
77	Tipton	40	8	13%	14.4	106
78	Grainger	37	13	14%	10.2	58
79	Hawkins	37	11	18%	9.9	56
80	Rutherford	37	10	7%	14.7	80
81	Sumner	37	12	7%	13.3	77
82	Union	37	13	14%	10.8	55
83	Rhea	36	8	13%	14.8	74
84	Hamblen	35	11	16%	9	66
85	Cocke	31	10	17%	8.1	60
86	Williamson	31	12	4%	11.6	77
87	Blount	30	7	18%	11.9	67
88	Bradley	30	6	13%	13.8	84
89	Loudon	30	7	16%	12.5	80
90	Fayette	28	7	7%	13.9	101
91	Meigs	27	7	8%	14.3	80
92	Polk	27	8	16%	13	64
93	Jefferson	26	9	14%	9.1	74
94	Sevier	18	10	8%	11.6	47
95	Monroe	17	8	11%	12.1	61

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