Carter County, Oklahoma
Shrink-swell clay limits houses without basements on 23% of Carter County's mapped land, a higher share than 74% of US counties. A shallow water table limits basements on 3%.
48.6% of the county is in drought on the October 13, 2026 Drought Monitor map, down from 100% a week earlier. FEMA's flood data list 12 flood losses here since 2016. 54% of homes were built before 1980, against 50% nationally; the median home dates from 1978.
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 Carter County
| Expansive clay (limits slab homes) | 23.1% |
| High water table (limits basements) | 3.1% |
| Septic fields very limited | 60.5% |
| Clay swell (LEP, by area) | 5.0% |
| High-swell land (LEP 6%+) | 23.1% |
| Mapped soil | 533,888 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Windthorst | 17% | 37% |
| Weatherford | 16% | n/a |
| Konsil | 10% | n/a |
| Normangee | 5% | 72% |
| Kiti | 4% | n/a |
| Pulaski | 4% | n/a |
How we count · survey areas OK019 (2025-08-29)
What the numbers mean here
Clay swell averages a linear extensibility of 5.0% by land area here, and 23% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 23% of the mapped land.
Clay shrinks as it dries: 48.6% of the county is in drought on the latest map, and 23% of Carter County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 29.60 in, 8.66 in below the 1991-2020 average year of 38.26 in.
USDA rates 60% of the land very limited for septic absorption fields.
Drought
48.6% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 51 of the last 52 weeks; the most was 100% of its area, in 29 weeks, most recently on the October 6, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 48.6% |
| D2 severe or worse | 13.9% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
12 flood losses since 2016, $620,903 paid. The worst year was 2018, with 3.
| Year | Flood losses |
|---|---|
| 2016 | 3 |
| 2017 | 2 |
| 2018 | 3 |
| 2019 | 1 |
| 2020 | 0 |
| 2021 | 1 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 1 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 38.26 in |
| 12 months to August 2026 | 29.60 in (-8.66) |
| 2025 | 43.77 in (+5.51) |
| Wettest year since 1895 | 2015: 71.01 in |
| Driest year since 1895 | 1963: 18.22 in |
| Days with 1 inch or more, normal at HEALDTON 3 E (8 mi away) | 11.3 |
Homes
| Housing units | 21,624 |
| Median year built | 1978 |
| Built before 1980 | 54% |
| Built 2000 or later | 23% |
| Owner-occupied | 67% |
| Median value, owner-occupied | $168,500 |
| Single-family detached | 77% |
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 |
|---|---|---|---|
| Murray County, OK | 20 mi | 29% | 7% |
| Love County, OK | 20 mi | 17% | 2% |
| Garvin County, OK | 32 mi | 30% | 6% |
| Jefferson County, OK | 33 mi | 17% | 1% |
| Marshall County, OK | 33 mi | 30% | 1% |
| Stephens County, OK | 36 mi | 19% | 2% |
| Johnston County, OK | 36 mi | 21% | 19% |
| Cooke County, TX | 43 mi | 38% | 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