HILO — September rains were lighter than normal throughout East Hawaii, even setting a dryness record in Laupahoehoe, but gave Kona a much-needed boost of moisture.
The rain gauge in Laupahoehoe “posted its lowest September total on record,” according to the September Precipitation Summary released this week by the National Weather Service in Honolulu.
Laupahoehoe got less than an inch of rain in September. Normally, it gets more than 8. The least amount Laupahoehoe received in September before this year was 1.61 inches in 2004.
East Hawaii remained below normal throughout the region, said Kevin Kodama, NWS senior hydrologist.
“The whole Hamakua Coast has been very dry,” he said.
The state Department of Land and Natural Resources continues to list East Hawaii as “abnormally dry” on its Hawaii Drought Monitor page and the entire Hamakua Coast as being in “severe drought.”
In 2017, Laupahoehoe so far has received 45.43 inches of rain, 43 percent of its normal 106.45 inches. Papaikou received 88.69 inches in 2017, 59 percent of the 149.97 inches it normally gets by the end of September.
Hilo International Airport, for the year, has recorded 57.53 inches, 64 percent of its normal 89.88 inches for the year, according to the NWS.
Kona got 6.3 inches so far this year, 77 percent of the normal 13.79 inches. But September was a bright spot for the West Hawaii area. The Ellison Onizuka Kona International Airport gauge recorded more than double its normal September rainfall — 1.97 inches compared to the typical .84 of an inch.
That, Kodama said, might have helped Kona have fewer water-shortage problems while two deep wells weren’t functioning. He said the Kona area has actually been doing better lately, with the entire coffee belt looking relatively good for moisture accumulation.
Kodama said it was “an unusual September” for weather on the Big Island, and for Hawaii in general.
A weak cold front reached the islands Sept. 6. That’s the “earliest arrival in at least the last 18 years” of a cold front more typically associated with the wet season, he said.
“The average arrival date of the wet season’s first cold front in that 18-year time span is Oct. 19, while the latest was Dec. 4 in 2000,” according to the NWS Precipitation Summary.
Another unusual event was the arrival Sept. 12 of a weather pattern typically not seen until mid- to late-December, with heavy afternoon showers typical of the wet season, Kodama said.
In the months ahead for the Big Island, he said, “The drought will still be with us and probably get worse.”