The heat is on: Record high temperature recorded in Hilo this week

You know it’s hot when you don’t even have to move to break a sweat.

A new record high temperature of 89 degrees was recorded Monday at Hilo International Airport, surpassing the previous record of 88 degrees set in 1987 and tied in 1988 and 2020.

And, itʻs just not hot. Itʻs sticky hot. With a dew point of 74 degrees and relative humidity at 63% just before 1 p.m., the heat index said it felt like it was 97 degrees.

Daytime temperatures have soared into the mid to upper 80s for much of the past month in Hilo, according to data from the National Weather Service in Honolulu.

UPS driver Adam Asagra doesnʻt need a thermometer to know it is hot. For six years he has been driving one of the big brown trucks — without air conditioning — to deliver packages 8 to 12 hours a day.

Drivers normally keep both side doors open for airflow. But it doesn’t help on the hottest days, when the cargo hold turns into an oven and the 30-something Puna resident has to dig for packages.

“(The) heat has been alright temperature-wise, but when compounded with low winds and the humidity it feels quite oppressive,” Asagra said.

The heat index is the combined effect of air temperature and humidity. The higher the air temperature and relative humidity, the higher the heat index and the hotter it feels. And that’s in the shade. The heat index can be increased by up to 15 degrees If you are in direct sunlight.

The dew point also is a factor. The higher it is, the muggier it feels. The dew point is the temperature at or below which water droplets begin to condense and dew can form. When the dew point is greater than or equal to 65 degrees, the heat can become oppressive.

Tuesday and Wednesday, while no new high temp records were set either day in Hilo, it still was hot and muggy.

The high temperature Tuesday was 88 degrees, just two degrees shy of the record of 90 degrees for Oct. 11 set in 1977. The heat index just before noon made it feel more like 94 degrees. On Wednesday, the high temperature was 87 degrees, with the heat index reaching into the low 90s in the early afternoon.

Genki Kino, a meteorologist with the National Weather Service in Honolulu, told Big Island Now on Wednesday that the state has been in an extended blocking pattern because of a low pressure that’s been centered north of the islands. There also have been several low pressure systems pass to the north of Hawai‘i. This has caused the typical cooling trade winds to be cut off.

“That’s why we’ve been bringing in some higher moisture, so that’s what’s been producing those higher dew points and it’s been making things feel much warmer than it should be,” Kino said.

Relative humidity has reached as high as 96% in Hilo since Sunday, with dew points ranging between 61 and 75 degrees during the same period.

Kino said lighter wind patterns can persist during this time of year, but the heat and humidity during the past week isn’t normal for October.

“If we’re setting records, it’s probably not normal,” Kino said.

September was also a warm month in Hilo. The lowest high temperature of the month was 79 degrees Sept. 15. Highs got up to the mid to upper 80s for more than half of the month, according to the National Weather Service.

The closest Hilo came to breaking a record last month was Sept. 5. The high temperature reached 87 degrees that day, just two degrees shy of the record of 89 degrees for the date set in 2020.

It’s been so hot in Hilo lately that some residents who work outside might be finding solace in the usually hot — but less humid — conditions of the Big Island’s west side.

Brian Higgins, a 40-something who lives in Hilo and works at a construction site near the Four Seasons Resort Hualālai in Kailua-Kona, said heat is something he deals with daily on the job, but it’s a dry heat with almost zero humidity.

“This time of year, I prefer west side heat,” Higgins said. “It reminds me of the seasons we experienced on the mainland that we don’t get in Hilo.”

The construction site is about 75 yards from the ocean, so a cool ocean breeze also helps ease the sun’s punishment while he’s working.

Is there any relief coming from the hot, humid conditions for East Hawai‘i other than taking a dip at the beach, finding air conditioning or shoving your head in the freezer? Maybe a little.

“We’ll briefly get the trade winds back on Friday into Saturday,” Kino said. “But starting early next week again, we’re going to be back into some light wind pattern.”

There are a few longer-term, extended forecast models that show some stronger trade winds returning, but those aren’t always reliable. So it seems, for at least the near future, the heat and stickiness will continue.

“We’ll definitely cool down on Saturday, for sure,” Kino said, but added that the blocking pattern that’s been in place will continue.

The good news: dew points will be lower by next Wednesday afternoon.

“So it probably won’t feel as warm as this week,” Kino said. “But it will definitely still feel warm.”