Hardin County, Ohio
A shallow water table limits basements on 97% of Hardin County's mapped land, a higher share than 99% of US counties and the 2nd highest of 88 Ohio counties. Shrink-swell clay limits houses without basements on 35%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 2 flood losses here since 2016. 67% of homes were built before 1980, against 50% nationally; the median home dates from 1969.
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 Hardin County
| Expansive clay (limits slab homes) | 34.7% |
| High water table (limits basements) | 96.8% |
| Septic fields very limited | 98.3% |
| Clay swell (LEP, by area) | 4.9% |
| High-swell land (LEP 6%+) | 8.5% |
| Mapped soil | 301,472 acres |
How we count · survey areas OH065 (2025-08-28)
What the numbers mean here
Clay swell averages a linear extensibility of 4.9% by land area here, and 8% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 35% of the mapped land.
On 97% of Hardin 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: 35.88 in, 1.81 in below the 1991-2020 average year of 37.69 in.
USDA rates 98% of the land very limited for septic absorption fields.
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 23 of the last 52 weeks; the most was 100% of its area, in 2 weeks, most recently on the October 28, 2025 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
2 flood losses since 2016, $79,421 paid. The worst year was 2019, with 1.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 1 |
| 2019 | 1 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 37.69 in |
| 12 months to August 2026 | 35.88 in (-1.81) |
| 2025 | 32.82 in (-4.87) |
| Wettest year since 1895 | 2011: 53.40 in |
| Driest year since 1895 | 1934: 21.59 in |
| Days with 1 inch or more, normal at HUNTSVILLE 3N (15 mi away) | 7.8 |
Homes
| Housing units | 12,917 |
| Median year built | 1969 |
| Built before 1980 | 67% |
| Built 2000 or later | 14% |
| Owner-occupied | 75% |
| Median value, owner-occupied | $151,200 |
| Single-family detached | 76% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Hardin County
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Logan County, OH | 20 mi | 26% | 81% |
| Wyandot County, OH | 22 mi | 30% | 90% |
| Hancock County, OH | 24 mi | 33% | 93% |
| Allen County, OH | 24 mi | 31% | 93% |
| Marion County, OH | 26 mi | 40% | 92% |
| Union County, OH | 30 mi | 25% | 97% |
| Auglaize County, OH | 30 mi | 29% | 94% |
| Putnam County, OH | 35 mi | 66% | 96% |
Sources: USDA SSURGO (August 28, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status