Osceola County, Iowa
A shallow water table limits basements on 76% of Osceola County's mapped land, a higher share than 86% of US counties. Shrink-swell clay limits houses without basements on 21%.
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. 82% of homes were built before 1980, against 50% nationally; the median home dates from 1955.
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 Osceola County
| Expansive clay (limits slab homes) | 21.1% |
| High water table (limits basements) | 76.1% |
| Septic fields very limited | 94.7% |
| Clay swell (LEP, by area) | 4.6% |
| High-swell land (LEP 6%+) | 14.8% |
| Mapped soil | 255,400 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Clarion | 10% | 61% |
| Everly | 10% | n/a |
| Primghar | 9% | n/a |
| Sac | 8% | n/a |
| Wilmonton | 8% | n/a |
| Nicollet | 8% | n/a |
How we count · survey areas IA143 (2025-09-09)
What the numbers mean here
Clay swell averages a linear extensibility of 4.6% by land area here, and 15% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 21% of the mapped land.
On 76% of Osceola 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: 22.61 in, 7.90 in below the 1991-2020 average year of 30.51 in.
USDA rates 95% 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 13 of the last 52 weeks; the most was 100% of its area, in 7 weeks, most recently on the April 7, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 10.1% |
| 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, $21,352 paid. The worst year was 2024, with 2.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 2 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 30.51 in |
| 12 months to August 2026 | 22.61 in (-7.90) |
| 2025 | 29.31 in (-1.20) |
| Wettest year since 1895 | 2018: 49.30 in |
| Driest year since 1895 | 1958: 15.65 in |
| Days with 1 inch or more, normal at SIBLEY (6 mi away) | 6.3 |
Homes
| Housing units | 2,868 |
| Median year built | 1955 |
| Built before 1980 | 82% |
| Built 2000 or later | 9% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $122,600 |
| Single-family detached | 88% |
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 |
|---|---|---|---|
| O'Brien County, IA | 20 mi | 47% | 64% |
| Nobles County, MN | 22 mi | 10% | 90% |
| Dickinson County, IA | 22 mi | 10% | 75% |
| Lyon County, IA | 29 mi | 18% | 37% |
| Jackson County, MN | 32 mi | 25% | 85% |
| Clay County, IA | 32 mi | 32% | 77% |
| Sioux County, IA | 34 mi | 26% | 35% |
| Rock County, MN | 37 mi | 24% | 54% |
Sources: USDA SSURGO (September 9, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status