It’s gotten hot in Hawaii.

Last year was the hottest ever in Honolulu. There were 135 daily temperature records set statewide in 2019.

But some areas are definitely hotter than others. And now, for Oahu at least, you can see that discrepancy with the city’s new heat-mapping tool.

Officials unveiled the results of Honolulu’s first-ever community heat assessment Wednesday, which identifies hot spots in neighborhoods around the island.

Honolulu officials have mapped the heat around Oahu with help from NOAA and other partners. Oahu Community Heat Map

It’s more than just being uncomfortable or a little sweaty. As Jim Howe, the city’s director of emergency services, said, it’s a serious public health risk.

“We need to be vigilant and ensure that our community is well informed regarding the dangers that heat waves can pose to our citizens and our health system,” he said. “In cities like Paris and Chicago we’ve seen hundreds of vulnerable citizens die when the temperature spikes and doesn’t come down.”

Data was collected by community volunteers and city personnel on Aug. 31. The maximum heat index recorded was 107.3 degrees at the Waimalu Plaza Shopping Center, a county news release says. Other neighborhoods with afternoon heat indices around 105 degrees included: Ala Moana, Kahala, Hawaii Kai, Waimanalo, Maili, Nanakuli and Pearl Ridge.

The rising thermometer doesn’t surprise those who have followed the warnings of climate scientists for years. The planet is warming, the ocean is warming. Trade winds are weakening.

Makena Coffman, chair of the City Climate Change Commission, cautioned that the rate of warming due to climate change is also increasing rapidly.

The air in Hawaii is now warming at a rate of 0.3°F each decade, she said in the release. That’s four times faster than 50 years ago.

“We clearly need to plan now for an even hotter future,” Coffman said.

“Climate change requires all hands on deck and the City can’t do this alone,” said Josh Stanbro, Honolulu’s chief resilience officer in the release. “We are thankful to the resident volunteers and partners that helped us capture this data, and now we need help to turn the recommendations in the Oahu Resilience Strategy into reality to protect ourselves as the mercury rises higher and higher.”

Mayor Kirk Caldwell said at a news conference that the public and private sectors need to continue planting more trees to not only help cool parts of the island by offering shade, but also to sequester some of the carbon emissions that are heating up the planet.

Officials said planting trees isn’t some hippie, tree-hugging exercise. It’s about human safety and protecting people from record heat, a top natural killer in the U.S.

The preliminary community heat assessment report is available here.

Help power our public service journalism

As a local newsroom, Civil Beat has a unique public service role in times of crisis.

That’s why we’re committed to a paywall-free website and subscription-free content, so we can get vital information out to everyone, from all communities.

We are deploying a significant amount of our resources to covering the Maui fires, and your support ensures that we can pivot when these types of emergencies arise.

Make a gift to Civil Beat today and help power our nonprofit newsroom.

About the Author