A layer of smoke descended over Singapore on Thursday, blown from Southeast Asia’s pockets of raging bush fires and causing the island’s air quality to approach unhealthy levels, the government said.

The pollutant standards index (PSI) hit a high of 95 on Thursday, almost in the unhealthy range, the National Environment Agency said on its website. It averaged 61 on Thursday, the highest daily average this year.

“The prevailing winds are blowing some smoke haze from hot spots from peninsular Malaysia and Sumatra,” the agency said, referring to the Indonesian island of Sumatra and adding that Singapore’s bush fires also contributed to the hazy skies.

Singapore was hit by its worst dry spell in 29 years last month, sparking rare bush fires in the densely populated Southeast Asian island just 140 km (85 miles) north of the equator. February was the driest month since 1976.

“The haziness is expected to persist from time to time over the next few days as the wind conditions are light and not able to fully disperse the smoke haze particles,” the agency said.

But the air quality was not expected to reach an unhealthy range as defined by a PSI reading of more than 100, it said.