History of Fire

Over the past decade, Hawai'i has experienced an average of >1,000 ignitions burning >20,000 acres (8,000 ha) each year across the main inhabited islands.  Fire response agencies are able to contain 90% of wildfire ignitions to less than one acre in size, but large fires (>1000 acres) have occurred on all islands, and happen multiple times each year across the state.

Hawai‘i Fire History and Agricultural Decline (Credit: Trauernicht & HWMO)
Hawaii 1999 - 2023 fires

Large Fire Perimeter Data for Hawai'i

This data set contains polygons of wildland fire perimeters for the main Hawaiian Islands from 1999 to 2022. It compiles prior mapping efforts by different organizations with fires mapped from 2012 onwards by Dr. Clay Trauernicht ([email protected]) in the Department of Natural Resources and Environmental Management (NREM) at the University of Hawai'i at Mānoa.  The data tracks and maps all fires greater than or equal to 20 hectares (50 acres), but some smaller fires are be included.

NOTE ON DATA USE AND DISTRIBUTION: We actively encourage use of this data set for scientific purposes and planning by communities, natural resource managers, and emergency response agencies. Users are prohibited from any commercial, non-free resale, or redistribution without explicit written permission from Clay Trauernicht. Download Fire Perimeters HERE

Wildfire Threats and Impacts

Nearly all fires in Hawai'i are human-caused and they often pose threats to communities and natural and cultural resources.  Having evolved in the absence of frequent fires, Hawai'i's native ecosystems are particularly vulnerable to fire disturbance, which is often associated with the spread and establishment of nonnative grass and shrub species.

Wildfire Drivers

The primary drivers of fire occurrence are: frequent, mostly human-caused ignitions; expansion of nonnative, fire-prone grasslands and shrublands over c. 25% of state land area; and strong rain shadow effects and episodic drought create which create year-round fire weather.

Statewide Wildfire Ignitions (2016)
Palehua, O`ahu, Aug 2014 (Credit: Clay Trauernicht)

Recent Resources For Hawai‘i

Moisture availability and ecological restoration limit fine fuels and modelled wildfire intensity following non-native ungulate removal in Hawaii (Zhu et al, 2021)

August 3, 2006

We measured fuels (live and dead fuel loads, type, height and continuity) and modelled potential wildfire behaviour (flame height and rate of spread) inside and outside of 13 ungulate exclosures, three of which received active ecological restoration (e.g. planting of native shrubs and trees), across a 2,740 mm mean annual rainfall (MAR) gradient on the Island of Hawaii. Differences in fuel characteristics and modelled wildfire behaviour inside versus outside of ungulate exclosures were assessed using linear mixed effects analyses.