Hawai‘i Island
Hawaiʻi Island is unique in that it is the only Hawaiian island with ongoing active volcanic eruptions. However, humans are still by far the leading cause of wildfire ignitions. The majority of wildfires on Hawaiʻi Island are caused by human error or arson, especially near developments, power line right of ways, and along roadsides.
Fire Today
Rainfall follows the typical pattern of the Hawaiian Islands, with more rain along the eastern windward coast. Mauna Kea and Mauna Loa create a rain shadow that results in drier conditions on the western leeward coasts. Most of the former sugar plantation lands are on the wetter windward side of the island, along the Hāmākua Coast. Despite this location, there is a long history of fires in the area. It was the large 1901 Hāmākua coast fire that was the impetus for keeping wildfire records in Hawaiʻi. >> READ MORE
On the leeward side, the Kohala area is particularly fire-prone. This drier region with large areas of fallow pasture and agricultural land has a high rate of ignitions vis-a-vis human infrastructure, as well as more regular large fires.
Fires > 50 Acres 1999-2018, Hawai‘i Island (Credit: UH Wildland Fire)
The growing footprint of these grass-dominated fallow agricultural lands combined with increasing human population increases the risk of wildfire across the island. The hazardous vegetation and high number of ignitions is exacerbated by climate change creating more frequent drought conditions.
Seasonal variation in rainfall also affects both ignitions and the extent of areas which burn. Particularly wet periods over a rainy season can, counterintuitively, significantly elevate hazard levels. Increased precipitation may lead to a surplus of vegetation growth, becoming potential fuel during subsequent drier periods, thereby elevating the risk of large wildfires. Given the changing wind and rainfall patterns arising from climate change, this may lead to increased risk.
Hawai‘i Island Average Acres and Ignitions (2012-2020)
Plans & Images
Leilani Fire, August 12, 2022 (Credit: Hawai‘i DLNR)
Recent Resources For Hawai‘i
Author Clay Trauernicht provides a spatial fire occurrence models to reveal the relative influence of multiple drivers, and discusses rainfall-vegetation interactions as a key predictor of fire risk variability as well as future drying predictions with climate change.
What: Observations and experiments on tropical grasses, including information on different grass species and on herbicide timing, application method, and ingredients. James Leary presents on over a decade of observations…
This 2-page fact sheet explains the problem of wildfire on tropical islands as it intersects with watershed and marine resource health, invasive species, climate and weather. Tags: Hawaii, Climate &…