Ogle County, Illinois
A shallow water table limits basements on 35% of Ogle County's mapped land, a higher share than 53% of US counties. Shrink-swell clay limits houses without basements on 10%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 30 flood losses here since 2016. 63% of homes were built before 1980, against 50% nationally; the median home dates from 1972.
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 Ogle County
| Expansive clay (limits slab homes) | 10.0% |
| High water table (limits basements) | 34.7% |
| Septic fields very limited | 58.0% |
| Clay swell (LEP, by area) | 4.2% |
| High-swell land (LEP 6%+) | 5.9% |
| Mapped soil | 488,520 acres |
How we count · survey areas IL141 (2025-08-31)
What the numbers mean here
On 35% of Ogle 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: 33.86 in, 4.49 in below the 1991-2020 average year of 38.35 in.
USDA rates 58% 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 29 of the last 52 weeks; the most was 100% of its area, in 8 weeks, most recently on the June 9, 2026 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
30 flood losses since 2016, $564,248 paid. The worst year was 2017, with 16.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 16 |
| 2018 | 5 |
| 2019 | 1 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 1 |
| 2023 | 2 |
| 2024 | 2 |
| 2025 | 1 |
| 2026 to date | 2 |
Rain
| Average year, 1991-2020 | 38.35 in |
| 12 months to August 2026 | 33.86 in (-4.49) |
| 2025 | 30.85 in (-7.50) |
| Wettest year since 1895 | 2009: 51.33 in |
| Driest year since 1895 | 1910: 21.25 in |
| Days with 1 inch or more, normal at OREGON (3 mi away) | 10.8 |
Homes
| Housing units | 22,682 |
| Median year built | 1972 |
| Built before 1980 | 63% |
| Built 2000 or later | 16% |
| Owner-occupied | 75% |
| Median value, owner-occupied | $189,200 |
| Single-family detached | 83% |
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 |
|---|---|---|---|
| Lee County, IL | 20 mi | 14% | 66% |
| Winnebago County, IL | 22 mi | 9% | 28% |
| Stephenson County, IL | 28 mi | 13% | 24% |
| DeKalb County, IL | 30 mi | 28% | 98% |
| Carroll County, IL | 31 mi | 13% | 17% |
| Boone County, IL | 32 mi | 6% | 55% |
| Whiteside County, IL | 36 mi | 2% | 40% |
| Rock County, WI | 45 mi | 5% | 31% |
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