Keweenaw County, Michigan
A shallow water table limits basements on 31% of Keweenaw County's mapped land, a higher share than 50% of US counties. Shrink-swell clay limits houses without basements on 0%.
32.7% 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. 66% of homes were built before 1980, against 50% nationally; the median home dates from 1961.
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 Keweenaw County
| Expansive clay (limits slab homes) | 0.0% |
| High water table (limits basements) | 31.1% |
| Septic fields very limited | 43.9% |
| Clay swell (LEP, by area) | 0.6% |
| High-swell land (LEP 6%+) | 0.1% |
| Mapped soil | 787,885 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Montreal | 5% | n/a |
| Arcadian | 4% | n/a |
| Michigamme | 4% | n/a |
| Munising | 2% | n/a |
| Paavola | 2% | n/a |
| Skanee | 2% | n/a |
How we count · survey areas MI605 (2025-09-04), MI606 (2025-09-04)
What the numbers mean here
On 31% of Keweenaw 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: 28.94 in, 1.36 in below the 1991-2020 average year of 30.30 in.
Drought
32.7% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 3 of the last 52 weeks; the most was 32.7% of its area, in 3 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 | 32.7% |
| 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 Keweenaw County since 2016.
Rain
| Average year, 1991-2020 | 30.30 in |
| 12 months to August 2026 | 28.94 in (-1.36) |
| 2025 | 29.83 in (-0.47) |
| Wettest year since 1895 | 1968: 40.70 in |
| Driest year since 1895 | 1923: 19.83 in |
| Days with 1 inch or more, normal at COPPER HARBOR (23 mi away) | 3.2 |
Homes
| Housing units | 2,305 |
| Median year built | 1961 |
| Built before 1980 | 66% |
| Built 2000 or later | 15% |
| Owner-occupied | 91% |
| Median value, owner-occupied | $169,800 |
| Single-family detached | 96% |
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 |
|---|---|---|---|
| Houghton County, MI | 29 mi | 2% | 66% |
| Baraga County, MI | 46 mi | 1% | 53% |
| Ontonagon County, MI | 57 mi | 22% | 78% |
| Marquette County, MI | 63 mi | 0% | 46% |
| Iron County, MI | 83 mi | 0% | 57% |
| Gogebic County, MI | 91 mi | 1% | 84% |
| Dickinson County, MI | 96 mi | 0% | 36% |
| Cook County, MN | 97 mi | 3% | 45% |
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