An unusually wet May helped to make up for a dry start to the year on some parts of Hawaii Island.
Three areas along the windward slopes of the Big Island, including Piihonua, Hakalau and Honokaa, recorded their highest May rainfall totals since 2006, according to data provided by Kevin Kodama, senior hydrologist with the National Weather Service in Honolulu.
“Earlier in the year, it was fairly dry on the windward side,” he said Wednesday. “But it’s been a wet spring for you. We’re seeing you sort of catching up from deficits earlier in the year.”
The U.S. Geological Survey rain gauge at the Saddle Road quarry site posted the highest monthly rainfall total, collecting 24.89 inches, or nearly 250 percent of its usual May average.
Piihonua received 16.7 inches, or 124 percent of its May average; Hakalau saw 7.55 inches, or 166 percent of average; and Honokaa saw 10.08 inches, or 152 percent of average.
Glenwood also had a big month, with 19.97 inches of rain, or 126 percent of average.
The Hilo airport area was on target, with 7.75 inches of rain in the month of May, representing 95 percent of its average. Pahoa also had a near-normal May, with 8.5 inches of rainfall, or 96 percent of average.
Meanwhile, however, “some of the leeward areas are drying out,” Kodama said.
Kona airport, Kealakekua, South Point, Waimea and Mauna Loa rain gauges were all below 50 percent of their May averages, with Kona seeing only .02 inches of rain last month.
The Big Island still has a way to go to make up for the rain deficit built up since the beginning of the year, Kodama said.
Only four rain gauges out of a total of 51 are at 100 percent or more of year-to-date rainfall averages, according to the National Weather Service data. They were Honaunau, with 22.57 inches accumulated since Jan. 1; Mauna Loa, with 10.63 inches; Kawainui Stream, with 84.82 inches; and Saddle quarry, with 65.74 inches.
In a regular update issued for the last week of May, the U.S. Department of Agriculture reported that 61 percent of the state remained classified as “abnormally dry or drier,” with Ka‘u pastures beginning to show signs of drying.
“On the Big Island, the South Kona district has received light precipitation over the last week which continues to benefit various orchard crops,” the update reads. “Coffee crops are progressing well with a good fruit set in leeward districts. Interior pastures in the Hamakua District are green and appear in good condition, although some pastures have a lot of fire-weed. Ka’u pastures are beginning to dry out in lower elevations.”
Kodama said that Wednesday’s rain could help stabilize the situation in Ka‘u, however.
“They’re getting somewhat decent rain today, so that will help,” he said.
Email Colin M. Stewart at cstewart@hawaiitribune-herald.com.