New Year's celebrations in Hawai'i are all about tradition: fireworks, noise and, for a single hour every year in Pearl City, some of the worst air quality in the state.

It was no different this year and even though state health officials yesterday announced some of the best overall New Year's air quality in recent years, they still had to shrug when it came to Pearl City.

Daily averages at four Health Department monitoring stations were lower than last year — even in Pearl City. But at midnight, the folks in Pearl City were living in a cloud of smoke.

At 1 a.m. Sunday, the amount of particulates floating past the Health Department's monitoring station at 860 4th St. were more than 11 times greater than the daily average allowed by federal clean air regulations.

In the next hour, though, levels at the station plunged from the peak of 1,709 micrograms, thanks to wind and rain. The clearing conditions helped the Pearl City station record a daily average of 87 micrograms for the first day of the year, well below the federal daily average of 150 micrograms.

"We don't have any reason for that," said Wilfred Nagamine, chief of the Department of Health's Clean Air Branch. "There are all kinds of guesses and unless we do a full-blown investigation it is difficult to say."

Last year's levels were worse than the 2000 millennium celebration. At Pearl City, the daily average was 195 micrograms. And at 1 a.m. Jan. 1, 2005, the station peaked at 1,521 micrograms.

But levels this year were the best in at least three years, Nagamine said. The air began to thicken about 8 p.m. New Year's Eve and peaked at 1 a.m. New Year's Day. Conditions had improved everywhere by 2 a.m.

The state also monitors air quality in Liliha and Kapolei and in Kihei, Maui. It also monitors air quality in Honolulu, but could not this year because of construction on the building used.

"We are at the mercy of the weather," Nagamine said. "Fortunately this year, and I give it to the weathermen, they were on the nose. They predicted exactly that you would have trade winds in the late evening and light rains."

By comparison, the weather forecast for Dec. 31, 2004 included high-wind advisories and conditions that never materialized, he said.

"We cursed the weathermen," he said.

Even with the cleaner air, people still reported breathing difficulties. Honolulu Emergency Medical Services personnel responded to nine cases between 8 p.m. New Year's Eve and 2 a.m. New Year's Day, according to the department.

But as conditions cleared, their case load dropped: They only had four more cases before sunrise.

The Hawai'i chapter of the American Lung Association had feared the worst this year. Several days of light winds and dry conditions created a frenzy among people seeking free masks, said Claudia Clement, who oversees air quality issues for the chapter.

Instead of the usual 40 requests for masks on O'ahu, the chapter fielded more than 450 requests, Clement said.

"Everyone was really just being extra careful this year and expecting really bad smoke to linger because there were no trade winds," she said.

Nationally, the American Lung Association gives Hawai'i a "D" grade for air quality, Clement said, largely because of a small slice of time at the start of each year.

"Every year we have perfect air until the fireworks hit and they linger long and we get this bad grade," she said.

Reach Mike Gordon at mgordon@honoluluadvertiser.com.