Cimarron County, Oklahoma
Shrink-swell clay limits houses without basements on 22% of Cimarron County's mapped land, a higher share than 73% of US counties. A shallow water table limits basements on 2%.
3.3% of the county is in drought on the October 13, 2026 Drought Monitor map, down from 11% a week earlier. FEMA's flood data list no flood losses here since 2016. 75% of homes were built before 1980, against 50% nationally; the median home dates from 1963.
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 Cimarron County
| Expansive clay (limits slab homes) | 22.2% |
| High water table (limits basements) | 2.0% |
| Septic fields very limited | 38.2% |
| Clay swell (LEP, by area) | 3.5% |
| High-swell land (LEP 6%+) | 16.1% |
| Mapped soil | 1,178,586 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Dalhart | 23% | n/a |
| Sherm | 15% | 95% |
| Conlen | 12% | n/a |
| Gruver | 7% | n/a |
| Travessilla | 7% | n/a |
| Kim | 5% | n/a |
How we count · survey areas OK025 (2025-08-29)
What the numbers mean here
Clay swell averages a linear extensibility of 3.5% by land area here, and 16% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 22% of the mapped land.
Clay shrinks as it dries: 3.3% of the county is in drought on the latest map, and 22% of Cimarron County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 10.76 in, 5.99 in below the 1991-2020 average year of 16.75 in.
Drought
3.3% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 34 of the last 52 weeks; the most was 100% of its area, in 29 weeks, most recently on the September 29, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 3.3% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
FEMA's flood data list no flood losses in Cimarron County since 2016.
Rain
| Average year, 1991-2020 | 16.75 in |
| 12 months to August 2026 | 10.76 in (-5.99) |
| 2025 | 17.05 in (+0.30) |
| Wettest year since 1895 | 1941: 32.75 in |
| Driest year since 1895 | 1956: 7.83 in |
| Days with 1 inch or more, normal at BOISE CITY 2 E (3 mi away) | 4.3 |
Homes
| Housing units | 1,366 |
| Median year built | 1963 |
| Built before 1980 | 75% |
| Built 2000 or later | 6% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $98,600 |
| Single-family detached | 85% |
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 |
|---|---|---|---|
| Dallam County, TX | 33 mi | 15% | 1% |
| Baca County, CO | 38 mi | 28% | under 1% |
| Sherman County, TX | 48 mi | 40% | 2% |
| Morton County, KS | 49 mi | 2% | 1% |
| Union County, NM | 56 mi | 28% | 1% |
| Texas County, OK | 57 mi | 30% | 3% |
| Hartley County, TX | 63 mi | 14% | 1% |
| Stanton County, KS | 69 mi | 2% | 2% |
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