Thomas County, Kansas
USDA's soil survey flags shrink-swell clay on 3% of Thomas County's mapped land and a shallow water table under basements on 3%, both below the national shares of 15% and 29%. None 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. 78% of homes were built before 1980, against 50% nationally; the median home dates from 1967.
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 Thomas County
| Expansive clay (limits slab homes) | 2.9% |
| High water table (limits basements) | 2.9% |
| Septic fields very limited | 15.0% |
| Clay swell (LEP, by area) | 3.9% |
| High-swell land (LEP 6%+) | 4.4% |
| Mapped soil | 687,757 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Keith | 55% | n/a |
| Ulysses | 15% | n/a |
| Buffalo Park | 8% | n/a |
| Kuma | 7% | n/a |
| Colby | 5% | n/a |
| Goshen | 2% | n/a |
How we count · survey areas KS193 (2025-08-27)
What the numbers mean here
Rain over the 12 months to August 2026: 21.54 in, 1.14 in above the 1991-2020 average year of 20.40 in.
With shrink-swell clay on 3% and a shallow water table on 3% of the land, the soil survey points to neither problem across most of Thomas County; conditions still vary lot by lot.
Drought
0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 13 of the last 52 weeks; the most was 100% of its area, in 9 weeks, most recently on the June 16, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0.2% |
| D1 moderate drought or worse | 0% |
| 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 Thomas County since 2016.
Rain
| Average year, 1991-2020 | 20.40 in |
| 12 months to August 2026 | 21.54 in (+1.14) |
| 2025 | 20.64 in (+0.24) |
| Wettest year since 1895 | 1915: 31.78 in |
| Driest year since 1895 | 1956: 10.07 in |
| Days with 1 inch or more, normal at COLBY 1SW (3 mi away) | 4.5 |
Homes
| Housing units | 3,575 |
| Median year built | 1967 |
| Built before 1980 | 78% |
| Built 2000 or later | 5% |
| Owner-occupied | 75% |
| Median value, owner-occupied | $172,700 |
| 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 |
|---|---|---|---|
| Rawlins County, KS | 30 mi | 2% | 2% |
| Logan County, KS | 31 mi | 5% | 2% |
| Sherman County, KS | 33 mi | 3% | 3% |
| Sheridan County, KS | 35 mi | 2% | 2% |
| Gove County, KS | 44 mi | 11% | 1% |
| Decatur County, KS | 45 mi | 3% | 2% |
| Cheyenne County, KS | 45 mi | 3% | 2% |
| Wallace County, KS | 47 mi | 4% | 3% |
Sources: USDA SSURGO (August 27, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status