McNairy County, Tennessee
A shallow water table limits basements on 38% of McNairy County's mapped land, a higher share than 56% of US counties. Shrink-swell clay limits houses without basements on 5%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 4 flood losses here since 2016. 46% of homes were built before 1980, against 50% nationally; the median home dates from 1983.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under McNairy County
| Expansive clay (limits slab homes) | 5.3% |
| High water table (limits basements) | 37.7% |
| Septic fields very limited | 97.0% |
| Clay swell (LEP, by area) | 2.1% |
| High-swell land (LEP 6%+) | 6.5% |
| Mapped soil | 359,400 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Smithdale | 36% | 0% |
| Luverne | 12% | n/a |
| Enville | 8% | n/a |
| Bibb | 7% | n/a |
| Iuka | 6% | n/a |
| Silerton | 4% | n/a |
How we count · survey areas TN109 (2025-08-29)
What the numbers mean here
On 38% of McNairy County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 42.90 in, 13.95 in below the 1991-2020 average year of 56.85 in.
USDA rates 97% of the land very limited for septic absorption fields.
Drought
100% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 37 of the last 52 weeks; the most was 100% of its area, in 14 weeks, most recently on the October 13, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 100% |
| D2 severe or worse | 100% |
| D3 extreme or worse | 34.1% |
| D4 exceptional | 0% |
Flood losses since 2016
4 flood losses since 2016, $695,669 paid. The worst year was 2020, with 4.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 4 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 56.85 in |
| 12 months to August 2026 | 42.90 in (-13.95) |
| 2025 | 50.34 in (-6.51) |
| Wettest year since 1895 | 2018: 72.08 in |
| Driest year since 1895 | 1941: 35.76 in |
| Days with 1 inch or more, normal at SELMER (2 mi away) | 18.4 |
Homes
| Housing units | 12,327 |
| Median year built | 1983 |
| Built before 1980 | 46% |
| Built 2000 or later | 24% |
| Owner-occupied | 80% |
| Median value, owner-occupied | $161,800 |
| Single-family detached | 78% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Chester County, TN | 17 mi | 4% | 45% |
| Alcorn County, MS | 20 mi | 2% | 63% |
| Hardin County, TN | 21 mi | 2% | 36% |
| Hardeman County, TN | 24 mi | 7% | 39% |
| Madison County, TN | 33 mi | 0% | 46% |
| Henderson County, TN | 35 mi | 1% | 40% |
| Tippah County, MS | 35 mi | 14% | 49% |
| Tishomingo County, MS | 35 mi | 0% | 28% |
Sources: USDA SSURGO (August 29, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status