The vog has finally cleared over the Hawaiian islands. But the number of muggy and hazy days is on the incline, according to Hawaii News Now. 

A study published this summer by University of Hawaii professor Pao-Shin Chu found a dramatic decrease in the number of days with northeast trade winds. 

The study began on a hunch from Pao-Shin Chu, who moved to Hawaii in 1985. “Over the last 27 years, I just feel that the trade winds do not blow as much as they used to,” he said.

Chu also is a professor of meteorology at UH and is the head of the Hawaii State Climate Office. He was one of the scientists who looked at and analyzed 37 years of wind speed and direction data recorded at the four major airports in Hawaii: Lihue, Honolulu, Kahului and Hilo. They also looked at data from the four major weather buoys in waters around the state.

The analysis showed a decrease in the number of northeast trade wind days per year overall from 1973 to 2009, with the biggest decrease in Honolulu. “We used to have 291 days of northeast trades at Honolulu Airport, but now it dropped to only 210 days,” Chu said.