As wildfires continue to rage in many parts of the North and a district in southern Yala province, both parts of the country are being affected by the haze the fires produce.
Many parts of Betong, the southernmost district in Yala, were shrouded in thick haze yesterday, prompting complaints of eye irritation and respiratory problems from locals.
A warning telling the public to wear a face mask had been issued by local officials, while visibility was down and motorists were told to drive more carefully.
PM2.5 (fine dust) pollution levels have surpassed the "safety" threshold of 50 microgrammes per cubic metre (µg/m3) in Krabi, Satun and Yala since Sunday, according to data published on www.airthai.in.th.
According to the Prince of Songkla University's air pollution and health impact research station, the average PM2.5 levels in the South have ranged from 50 to 55µg/m3 since Saturday.
Key factors in the worsening air quality situation include northeast winds blowing haze from the Indian Ocean and certain parts of Myanmar, Cambodia and Vietnam, the station said.
Locally in the North, several wildfires continued including in Chiang Rai and Lampang, where winds have apparently made the situation worse since Sunday night.
A wildfire in the Mae Puem National Park in Muang district of Chiang Rai had intensified since Sunday night when it was fanned out by stronger winds towards the direction of an MCOT Plc television tower. It prompted the evacuation of staff at the station while firefighters contained the flames and saved the structure from being damaged as well by building a firebreak.
In Chiang Rai alone, wildfires continued yesterday, with 171 hotspots detected in Muang, Mae Suai, Mae Chan and Wiang Pa Pao districts.
In Lampang, a major wildfire in the Khelang Banphot National Park raged for a fifth day yesterday as efforts to put the blaze out did not appear to be successful, an informed source said.
An additional 100 firefighters have been deployed to help in the firefighting operation, the source said.
Worot Lieocharoensap, director of the meteorological centre in the western South, told a meeting that the hazy sky situation in the region is attributed to the transition between the dry and rainy seasons, not like the real haze situation being experienced in the North.
The weather condition will continue for one or two days or until the rain comes, he said.