2018 was Hilo’s third-wettest year on record

While windward rain gauges on Hawaii Island received mostly near- to above-average precipitation in December, the rest of the island had mostly below-average rainfall, according to the National Weather Service in Honolulu.

In East Hawaii, however, in rained enough in December to ensure that as 2018 drew to a close, Hilo International Airport had its third-wettest year on record since 1949.

Although only 9.97 inches of rain were measured in December, slightly below the average of 11.57 inches, the Hilo airport had 174.97 inches for the year — 138 percent above the average of 126.72 inches.

The record annual rain total for the airport is 211.22 inches in 1990, followed by 182.81 inches in 1994, according to a December precipitation summary prepared by NWS hydrologist Kevin Kodama.

Kodama, who has predicted a drier-than-normal wet season, said there was “nothing real dramatic” about the December rainfall totals.

The leeward side of the island was “pretty dry,” which is “consistent with the El Nino dryness that we were expecting.”

With just 0.18 inches of rain measured, Pahala tied its record for driest December, he said, noting that rainfall data for the town go back less than 30 years.

While the lack of rain was notable, Kodama said “usually you’d like to see a longer period of record to see long-term patterns … .”

The Pali 2 rain gauge in the Ka‘u desert had its lowest December rainfall total since 2005.

Rainfall totals for the year, however, ended up above average at most of the gauges on the Big Island, Kodama’s summary states.

Much of the rainfall can be attributed to Hurricane Lane in August, which dumped as much as 50 inches of rain in some East Hawaii areas, Tropical Storm Olivia in September, and other weather systems that brought heavy rain to East Hawaii.

“So when you get that much rain in that short period, (it) definitely boosts your numbers,” Kodama said of Hurricane Lane.

The Saddle Road Quarry gauge had the highest annual rainfall total — 364.79 inches, or 259 percent higher than the norm of 140.72 inches.

In West Hawaii, however, some annual rain totals were below average in 2018.

According to the provided data, gauges at the Ellison Onizuka Kona International Airport at Keahole measured no rain last month and 12.05 inches for the year, compared to the annual average of 18.39 inches.

At Kealakekua, rainfall totaled 45.13 inches in 2018, compared to an average of 56.24, and in Honaunau, rainfall measuring 55.07 inches was just slightly below the average of 56.14 inches.

Waikoloa had above-average rainfall in 2018 — 16.95 inches, compared to the average of 12.72 inches.

Although December was dry in Pahala, the community had above-average rainfall last year, with rain gauges capturing 86.89 inches, or 153 percent above the 57-inch average.

In East Hawaii, Laupahoehoe received 173.01 inches of rain, compared to an average of 143.93 inches; Piihonua saw 257.08 inches of rain last year, up over its average of 185.75 inches; Waiakea Uka had 249.91 inches, compared to an average 196.20 inches; Mountain View measured 260.53 inches, compared to an average of 172.40; Glenwood saw 248.62 inches, compared to an average of 233.53; and Pahoa received 219.48 inches, compared to the average of 136.83 inches.

Email Stephanie Salmons at ssalmons@hawaiitribune-herald.com.
Source: Hawaii Tribune Herald