Hawai‘i enters wet season drier than usual; El Niño conditions persist

The Hawaiian Islands are entering this year’s wet season drier than usual following several months of severe to exceptional drought — and conditions don’t appear to be changing.

The National Oceanic and Atmospheric Administration’s climate models favor below-average rainfall through the entire wet season, which runs October through April 2024. With 16% of the state already severely parched, experts say that could grow to 40% by the end of February.

This morning, Kevin Kodama, senior service hydrologist at the National Weather Service’s Honolulu Forecast Office, hosted a press conference discussing the outlook for this year’s wet season. He said El Niño conditions have been present since the spring and intensified during the summer.

That trend will continue in the coming months.

The current El Niño is likely to peak as a strong event and continue into spring, with a 3 in 10 chance of a “historically strong” event. Kodama said these events include a rise in ocean temperature. In 2015-16, these conditions resulted in mass coral bleaching throughout the state, with Hawai‘i losing more than half its live corals.

These short-term rainfall deficits also impact non-irrigated crops and pastures along with residents on rainfall catchment systems.

Toward the end of the wet season in March and April, Kodama said trade winds could pick up and push conditions to red flag warning level, creating out-of-season brush fires.

Kodama said there could still be some heavy rain coming through, adding the state is expecting rain sometime next week. There is also the potential of a tropical storm, as another hallmark of an El Niño is the extension of hurricane season.

Hurricane season in Hawai‘i normally runs from June 1 through Nov. 30.

The past dry season, which recorded near to below-average rainfall in most locations statewide, was considered the eighth driest in the past 30 years.

The 2023 dry season started a bit late, but drought developed in June, then spread and intensified through the rest of the season. Severe drought was seen in all four counties by the end of the dry season, which runs May through September.

Drought became extreme in leeward Maui and localized areas on the Big Island at the end of the dry season. Impacts included large brush fires on both islands, especially Aug. 8 when a blaze decimated West Maui’s old Hawaiian fishing village of Lāhainā, resulting in the deaths of more than 90 men, women and children.

Drought is expected to continue into the 2024 dry season. Other impacts include a higher likelihood of large North Shore surf events, especially in January and February.

The 2010 dry season was the driest on record in the past 30 years. Kodama said Kona coffee production was impacted that year, with him receiving reports of coffee trees dying.

The 2015 dry season was the wettest in the past 30 years.