Cotton County, Oklahoma
Shrink-swell clay limits houses without basements on 54% of Cotton County's mapped land, a higher share than 92% of US counties and the 2nd highest of 77 Oklahoma counties. A shallow water table limits basements on 4%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 3 flood losses here since 2016. 68% of homes were built before 1980, against 50% nationally; the median home dates from 1971.
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 Cotton County
| Expansive clay (limits slab homes) | 54.3% |
| High water table (limits basements) | 3.8% |
| Septic fields very limited | 68.8% |
| Clay swell (LEP, by area) | 5.7% |
| High-swell land (LEP 6%+) | 49.5% |
| Mapped soil | 419,801 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Foard | 17% | n/a |
| Vernon | 14% | n/a |
| Port | 13% | n/a |
| Tillman | 11% | 93% |
| Zaneis | 9% | n/a |
| Knoco | 4% | n/a |
How we count · survey areas OK033 (2025-08-29)
What the numbers mean here
Clay swell averages a linear extensibility of 5.7% by land area here, and 50% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 54% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 54% of Cotton County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 22.78 in, 8.88 in below the 1991-2020 average year of 31.66 in.
USDA rates 69% 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 52 of the last 52 weeks; the most was 100% of its area, in 35 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 | 82.6% |
| D4 exceptional | 1.2% |
Flood losses since 2016
3 flood losses since 2016, $59,622 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 | 1 |
| 2024 | 0 |
| 2025 | 2 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 31.66 in |
| 12 months to August 2026 | 22.78 in (-8.88) |
| 2025 | 37.51 in (+5.85) |
| Wettest year since 1895 | 2015: 49.89 in |
| Driest year since 1895 | 2011: 16.83 in |
| Days with 1 inch or more, normal at DUNCAN 10 W (19 mi away) | 10 |
Homes
| Housing units | 2,697 |
| Median year built | 1971 |
| Built before 1980 | 68% |
| Built 2000 or later | 11% |
| Owner-occupied | 80% |
| Median value, owner-occupied | $113,900 |
| Single-family detached | 83% |
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 |
|---|---|---|---|
| Comanche County, OK | 26 mi | 38% | 4% |
| Wichita County, TX | 28 mi | 43% | under 1% |
| Stephens County, OK | 32 mi | 19% | 2% |
| Tillman County, OK | 32 mi | 47% | 2% |
| Jefferson County, OK | 33 mi | 17% | 1% |
| Clay County, TX | 36 mi | 23% | 2% |
| Archer County, TX | 50 mi | 36% | under 1% |
| Wilbarger County, TX | 52 mi | 41% | under 1% |
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