Hawaiʻi had its second driest year in more than a century in 2025. About half the state experienced some level of drought, and average temperatures were up to a degree higher than normal across the islands.
Those data points come from the Hawaiʻi Climate Data Portal's first annual report, which offers a comprehensive look at weather and climate conditions in Hawaiʻi in 2025.
Local researchers launched the portal in 2022 with the goal of creating a central hub for Hawaiʻi climate data, said University of Hawaiʻi climate scientist and HCDP Director Ryan Longman.
He added that their first annual report was made possible by the roll-out of the Hawaiʻi Mesonet, a network of 100 climate stations across the state.
"That's given us this really high-quality data in places where that data did not exist before," Longman said.
HCDP is working to make local climate data accessible to the public at a time when federal sources of data are less reliable, according to Longman.
"We can't really count on the federal government anymore to provide us with data and information," he said.
He said he believes local data production is a key part of Hawaiʻi's resiliency efforts and critical to understanding how our climate is changing.
This annual report doesn't focus on climate trends — that's a project for next year, said Longman.
But he did point out that four out of Hawaiʻi's five driest years have all occurred in the last decade. Researchers have also documented increases in the intensity and duration of droughts in the islands.
"So there's other evidence out there that's supporting that we are moving into this drier climate," he said.
