Coal County, Oklahoma
A shallow water table limits basements on 71% of Coal County's mapped land, a higher share than 82% of US counties and the highest of 77 Oklahoma counties. Shrink-swell clay limits houses without basements on 54%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list no flood losses here since 2016. 60% of homes were built before 1980, against 50% nationally; the median home dates from 1976.
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 Coal County
| Expansive clay (limits slab homes) | 53.7% |
| High water table (limits basements) | 70.8% |
| Septic fields very limited | 95.7% |
| Clay swell (LEP, by area) | 6.1% |
| High-swell land (LEP 6%+) | 61.8% |
| Mapped soil | 333,818 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Homa | 18% | n/a |
| Dennis | 11% | 100% |
| Wynona | 10% | n/a |
| Steedman | 9% | n/a |
| Clearview | 8% | n/a |
| Bates | 6% | n/a |
How we count · survey areas OK029 (2025-08-29)
What the numbers mean here
Clay swell averages a linear extensibility of 6.1% by land area here, and 62% 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 Coal County's mapped land has shrink-swell clay.
On 71% of Coal 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: 35.37 in, 10.00 in below the 1991-2020 average year of 45.37 in.
USDA rates 96% 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 46 of the last 52 weeks; the most was 100% of its area, in 30 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 | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
FEMA's flood data list no flood losses in Coal County since 2016.
Rain
| Average year, 1991-2020 | 45.37 in |
| 12 months to August 2026 | 35.37 in (-10.00) |
| 2025 | 47.34 in (+1.97) |
| Wettest year since 1895 | 2015: 79.85 in |
| Driest year since 1895 | 1963: 22.39 in |
| Days with 1 inch or more, normal at LEHIGH 4 SW (10 mi away) | 14.4 |
Homes
| Housing units | 2,585 |
| Median year built | 1976 |
| Built before 1980 | 60% |
| Built 2000 or later | 18% |
| Owner-occupied | 69% |
| Median value, owner-occupied | $115,700 |
| 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 |
|---|---|---|---|
| Atoka County, OK | 19 mi | 45% | 36% |
| Pontotoc County, OK | 25 mi | 28% | 15% |
| Johnston County, OK | 28 mi | 21% | 19% |
| Hughes County, OK | 33 mi | 31% | 43% |
| Pittsburg County, OK | 39 mi | 44% | 41% |
| Bryan County, OK | 43 mi | 42% | 19% |
| Seminole County, OK | 44 mi | 17% | 25% |
| Murray County, OK | 45 mi | 29% | 7% |
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