Kaua'i's Wai'ale'ale was drenched with more than 18 inches of rain during one 24-hour period last month, and 12 inches in a day a week later, but can it still claim the title of the wettest spot on the planet?

That depends on who's counting and on how they compile the figures.

"If it is not at the top, it should be very close to the top," said meteorologist Pao-Shin Chu, who is Hawai'i's state climatologist.

The National Weather Service cites Wai'ale'ale as the wettest, with a median rainfall of 486 inches.

"Mt. Wai'ale'ale receives 486 inches annually, the highest recorded annual average in the world. Mt. Wai'ale'ale has recorded annual rainfalls in excess of 620 inches," says the Web site for the agency's Lihu'e Airport weather station.

The Guinness World Records gives the title to a place called Mawsynram in Meghalaya, India, with 467.3 inches of annual rainfall. Presumably, Guinness has concluded Wai'ale'ale averages less than that.

Because weather changes in vast, multiyear cycles, getting a high average all depends on which years you choose to average.

Most Hawai'i experts concede that before the 1970s, Wai'ale'ale had a lock on the title, but that the Islands then went into three decades of drier weather. If you count only the past 30 years, you get a lower average for the Kaua'i mountain. If you include the 1940s though the 1960s, it's higher.

Most knowledgeable weather observers agree that Wai'ale'ale is just about perfectly situated for wetness. It sits in the Pacific, so there's moist air all around. The tradewinds are funneled by the Anahola and Ha'upu mountain ranges into the volcano's crater, and the breezes are then blown up to just above the 5,000-foot level, a perfect elevation for causing water droplets to condense and fall, said Tom Schroeder, a University of Hawai'i meteorologist.

Chu added that Kaua'i's roughly round shape means central Wai'ale'ale can get rain no matter from which direction the wind blows.

"The shape of the island can be important," he said.

Kaua'i is a little north of the other islands, and tends to get hit by more winter storms since many weather systems die out before hitting the more southerly islands. That adds to the total rainfall, Schroeder said.

"It seems as if the Guinness people have decided to accept India. But if they're ahead, I'd call it by a gnat's eyelash, with qualifications. There's enough uncertainty that you might as well call it a tie," he said.

If you have a question or concern about the Hawaiian environment, drop a note to Jan TenBruggencate at P.O. Box 524, Lihu'e, HI 96766 or jant@honoluluadvertiser.com. Or call him at (808) 245-3074.