In Chiang Rai province, the smog has been building up, although the amount of small particulate matter of up to 10 microns in diameter (PM10) was not still beyond the safe limit of below 120 microgram per one cubic metre.

Still, dense smog in the province has affected visibility.Chiang Rai governor Boonsong Techamaneesatit said the province aimed to reduce the haze problem by 30 per cent this haze season by authorities issuing a burning ban from February 17 to April 17.