THE HONOLULU COUNTY LAND BRIEF
Land in the
Humid Oxidic Soils on Low and Intermediate Rolling Mountain Slopes setting.
Honolulu County has 600.8 square miles of land in Hawaii. 6 mapped landscape regions meet across Honolulu County: Humid Oxidic Soils on Low and Intermediate Rolling Mountain Slopes, Humid and Very Humid Steep and Very Steep Mountain Slopes, Alluvial Fans and Coastal Plains, among others.
Windward lower and middle slopes on older Hawaiian islands include rolling volcanic terrain cut by steep gulches. Highly weathered surface materials and stream headwaters characterize this humid regional setting.
Regional context: Humid Oxidic Soils on Low and Intermediate Rolling Mountain Slopes ↗ · Regional mapping across the county footprint
Where the landscape changes
Honolulu County intersects 6 mapped regional units. The largest mapped shares are:
- Humid Oxidic Soils on Low and Intermediate Rolling Mountain Slopes23.9%
- Humid and Very Humid Steep and Very Steep Mountain Slopes22.2%
- Alluvial Fans and Coastal Plains17%
- Semiarid and Subhumid Low Mountain Slopes15.9%
- Very Stony Land and Rock Land11.7%
Humid and Very Humid Steep and Very Steep Mountain Slopes in Honolulu County
Steep ridges, deep gulches and canyons dissect the wetter mountain landscapes of older Hawaiian islands. Some higher plateaus support bogs within this strongly varied terrain.
Read the regional source ↗Alluvial Fans and Coastal Plains in Honolulu County
Low coastal plains and adjoining alluvial fans occur on older Hawaiian islands and central Maui's isthmus. These relatively gentle surfaces contrast with the islands' mountain slopes.
Read the regional source ↗Finding your parcel within Honolulu County
The atlas lists 55 cities, towns, townships, and Census communities associated with Honolulu County, including Urban Honolulu, East Honolulu, Pearl City. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Honolulu County by land and water
The Census records 1,565.4 square miles of water within Honolulu County, or 72.3% of its total area. That share is close to Honolulu County’s 72.3%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Honolulu County has 223.3 times the land area of nearby Makaha CDP (2.69 square miles). These areas describe boundaries, not comparable property prices.

