Fannin County, Texas
Shrink-swell clay limits houses without basements on 66% of Fannin County's mapped land, a higher share than 95% of US counties. A shallow water table limits basements on 23%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 31 flood losses here since 2016. 41% of homes were built before 1980, against 50% nationally; the median home dates from 1987.
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 Fannin County
| Expansive clay (limits slab homes) | 66.4% |
| High water table (limits basements) | 23.0% |
| Septic fields very limited | 83.5% |
| Clay swell (LEP, by area) | 7.5% |
| High-swell land (LEP 6%+) | 68.3% |
| Mapped soil | 575,916 acres |
How we count · survey areas TX147 (2025-09-04)
What the numbers mean here
Clay swell averages a linear extensibility of 7.5% by land area here, and 68% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 66% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 66% of Fannin County's mapped land has shrink-swell clay.
On 23% of Fannin 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: 34.80 in, 9.45 in below the 1991-2020 average year of 44.25 in.
USDA rates 84% 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 35 of the last 52 weeks; the most was 100% of its area, in 16 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 | 27.1% |
| D4 exceptional | 0% |
Flood losses since 2016
31 flood losses since 2016, $1.3 million paid. The worst year was 2018, with 16. Median water depth outside the building: 15.5 in.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 5 |
| 2018 | 16 |
| 2019 | 1 |
| 2020 | 5 |
| 2021 | 1 |
| 2022 | 0 |
| 2023 | 2 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 44.25 in |
| 12 months to August 2026 | 34.80 in (-9.45) |
| 2025 | 41.02 in (-3.23) |
| Wettest year since 1895 | 2015: 72.23 in |
| Driest year since 1895 | 1910: 18.19 in |
| Days with 1 inch or more, normal at TRENTON (17 mi away) | 13.9 |
Homes
| Housing units | 14,814 |
| Median year built | 1987 |
| Built before 1980 | 41% |
| Built 2000 or later | 31% |
| Owner-occupied | 79% |
| Median value, owner-occupied | $233,700 |
| Single-family detached | 78% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Fannin County
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Bryan County, OK | 27 mi | 42% | 19% |
| Delta County, TX | 29 mi | 77% | 15% |
| Lamar County, TX | 31 mi | 66% | 31% |
| Hunt County, TX | 32 mi | 78% | 17% |
| Grayson County, TX | 33 mi | 60% | 4% |
| Collin County, TX | 39 mi | 72% | 1% |
| Hopkins County, TX | 44 mi | 63% | 31% |
| Choctaw County, OK | 44 mi | 47% | 36% |
Sources: USDA SSURGO (September 4, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status