Hardin County, Illinois
A shallow water table limits basements on 41% of Hardin County's mapped land, a higher share than 59% of US counties. Shrink-swell clay limits houses without basements on 1%.
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. 59% of homes were built before 1980, against 50% nationally; the median home dates from 1974.
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) | 0.9% |
| High water table (limits basements) | 41.3% |
| Septic fields very limited | 82.7% |
| Clay swell (LEP, by area) | 3.5% |
| High-swell land (LEP 6%+) | 1.0% |
| Mapped soil | 115,980 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Alford | 20% | n/a |
| Wellston | 13% | under 1% |
| Grantsburg | 12% | n/a |
| Hosmer | 10% | over 99% |
| Berks | 5% | under 1% |
| Zanesville | 5% | 97% |
How we count · survey areas IL069 (2025-08-31)
What the numbers mean here
On 41% 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: 40.62 in, 8.22 in below the 1991-2020 average year of 48.84 in.
USDA rates 83% 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 10 of the last 52 weeks; the most was 100% of its area, in 8 weeks, most recently on the May 26, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 63.7% |
| 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 Hardin County since 2016.
Rain
| Average year, 1991-2020 | 48.84 in |
| 12 months to August 2026 | 40.62 in (-8.22) |
| 2025 | 49.73 in (+0.89) |
| Wettest year since 1895 | 1950: 69.53 in |
| Driest year since 1895 | 1963: 29.31 in |
| Days with 1 inch or more, normal at ROSICLARE 5NW (9 mi away) | 14 |
Homes
| Housing units | 2,337 |
| Median year built | 1974 |
| Built before 1980 | 59% |
| Built 2000 or later | 10% |
| Owner-occupied | 80% |
| Median value, owner-occupied | $103,800 |
| Single-family detached | 72% |
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 |
|---|---|---|---|
| Crittenden County, KY | 14 mi | 1% | 54% |
| Pope County, IL | 17 mi | 2% | 67% |
| Gallatin County, IL | 17 mi | 31% | 67% |
| Union County, KY | 20 mi | 4% | 53% |
| Livingston County, KY | 22 mi | 3% | 49% |
| Saline County, IL | 22 mi | 20% | 86% |
| Webster County, KY | 32 mi | 10% | 69% |
| Massac County, IL | 32 mi | 8% | 79% |
Sources: USDA SSURGO (August 31, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status