Audrain County, Missouri
A shallow water table limits basements on 98% of Audrain County's mapped land, a higher share than 99% of US counties and the 2nd highest of 115 Missouri counties. Shrink-swell clay limits houses without basements on 90%.
88% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 2 flood losses here since 2016. 65% of homes were built before 1980, against 50% nationally; the median home dates from 1970.
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 Audrain County
| Expansive clay (limits slab homes) | 90.0% |
| High water table (limits basements) | 97.7% |
| Septic fields very limited | 99.4% |
| Clay swell (LEP, by area) | 9.6% |
| High-swell land (LEP 6%+) | 89.1% |
| Mapped soil | 446,285 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Mexico | 35% | n/a |
| Leonard | 16% | n/a |
| Armstrong | 14% | over 99% |
| Putnam | 13% | n/a |
| Keswick | 7% | n/a |
| Belknap | 5% | n/a |
How we count · survey areas MO007 (2025-08-28)
What the numbers mean here
Clay swell averages a linear extensibility of 9.6% by land area here, and 89% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 90% of the mapped land.
Clay shrinks as it dries: 88% of the county is in drought on the latest map, and 90% of Audrain County's mapped land has shrink-swell clay.
On 98% of Audrain 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: 37.56 in, 3.87 in below the 1991-2020 average year of 41.43 in.
USDA rates 99% of the land very limited for septic absorption fields.
Drought
88% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 16 of the last 52 weeks; the most was 100% of its area, in 9 weeks, most recently on the March 3, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 88% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
2 flood losses since 2016, $503,661 paid. The worst year was 2025, with 2.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 2 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 41.43 in |
| 12 months to August 2026 | 37.56 in (-3.87) |
| 2025 | 33.37 in (-8.06) |
| Wettest year since 1895 | 2008: 61.11 in |
| Driest year since 1895 | 1901: 22.27 in |
| Days with 1 inch or more, normal at VANDALIA (20 mi away) | 10.7 |
Homes
| Housing units | 10,561 |
| Median year built | 1970 |
| Built before 1980 | 65% |
| Built 2000 or later | 14% |
| Owner-occupied | 72% |
| Median value, owner-occupied | $143,100 |
| Single-family detached | 80% |
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 |
|---|---|---|---|
| Monroe County, MO | 21 mi | 84% | 85% |
| Callaway County, MO | 27 mi | 54% | 63% |
| Montgomery County, MO | 28 mi | 67% | 76% |
| Ralls County, MO | 29 mi | 56% | 75% |
| Boone County, MO | 29 mi | 71% | 78% |
| Pike County, MO | 37 mi | 45% | 69% |
| Randolph County, MO | 38 mi | 83% | 85% |
| Shelby County, MO | 42 mi | 87% | 91% |
Sources: USDA SSURGO (August 28, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status