North Slope Borough, Alaska
A shallow water table limits basements on 67% of North Slope Borough's mapped land, a higher share than 79% of US counties and the highest of 22 Alaska counties. Shrink-swell clay limits houses without basements on 0%.
The soil survey maps 59% of the county's land area; these shares describe the mapped part. None of the county is in drought on the November 3, 2026 Drought Monitor map. FEMA's flood data list no flood losses here since 2016. 35% of homes were built before 1980, against 50% nationally; the median home dates from 1984.
Data as of November 3, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, November 3, 2026
of homes built before 1980
Soil under North Slope Borough
| Expansive clay (limits slab homes) | 0.0% |
| High water table (limits basements) | 67.1% |
| Septic fields very limited | 83.0% |
| Clay swell (LEP, by area) | 0.7% |
| High-swell land (LEP 6%+) | 0.0% |
| Mapped soil | 33,483,355 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Inigok | 1% | n/a |
| Nuiqsut | under 1% | n/a |
| Teshekpuk | under 1% | n/a |
| Anajuk | under 1% | n/a |
| Bodfish | under 1% | n/a |
| Poleakoon | under 1% | n/a |
How we count · survey areas AK747 (2025-09-02), AK753 (2025-09-02), AK758 (2025-09-02), AK760 (2025-09-02), AK761 (2025-09-02), AK762 (2025-09-02), AK763 (2025-09-02)
What the numbers mean here
On 67% of North Slope Borough'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: 15.18 in, 3.62 in above the 1991-2020 average year of 11.56 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 November 3, 2026 map. No part of the county was in drought in the last 52 weeks.
| Category, November 3, 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
FEMA's flood data list no flood losses in North Slope Borough since 2016.
Rain
| Average year, 1991-2020 | 11.56 in |
| 12 months to August 2026 | 15.18 in (+3.62) |
| 2025 | 15.84 in (+4.28) |
| Wettest year since 1925 | 1963: 16.92 in |
| Driest year since 1925 | 2007: 6.53 in |
Homes
| Housing units | 2,642 |
| Median year built | 1984 |
| Built before 1980 | 35% |
| Built 2000 or later | 15% |
| Owner-occupied | 49% |
| Median value, owner-occupied | $218,300 |
| Single-family detached | 71% |
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 |
|---|---|---|---|
| Northwest Arctic Borough, AK | 238 mi | 0% | 64% |
| Yukon-Koyukuk Census Area, AK | 285 mi | 0% | 62% |
| Fairbanks North Star Borough, AK | 379 mi | 0% | 56% |
| Denali Borough, AK | 409 mi | n/a | n/a |
| Nome Census Area, AK | 431 mi | 0% | 63% |
| Southeast Fairbanks Census Area, AK | 476 mi | 0% | 62% |
| Matanuska-Susitna Borough, AK | 509 mi | n/a | n/a |
| Kusilvak Census Area, AK | 565 mi | n/a | n/a |
Sources: USDA SSURGO (September 2, 2025) · US Drought Monitor (November 3, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status