People working outdoors such as tuk tuk and songtaew drivers in Chiang Mai province say the haze hovering over the North has affected their daily life.
"The smog affects visibility and my eyes and nose get irritated, so I have to wear a facemask while working," tuk tuk driver Artsanai Chaisuwan said yesterday, adding that the number of tourists in the area seemed to be lower.
"I hope they will visit Chiang Mai by Songkran," he said.
The smog situation yesterday improved and only three provinces experienced high levels of particulate matter with a maximum diameter of 10 microns, considered unsafe.
According to the Pollution Control Department, Mae Hong Son had 227 micrograms per cubic metre, Chiang Rai had 168 and Chiang Mai 148.
The Tourism Authority of Thailand's Chiang Mai office director, Wisut Buachum, said the smog had had little effect on Chiang Mai tourism.
Many pre-booked tourists knew about the smog but still visited, he said.
Wisut said only a handful of tour groups had cancelled visits and hotels had not experienced a drop in room reservations.
He said the situation should improve soon.
In related news, a bio-mass landfill at Chiang Mai University caught fire on Wednesday night but was put out within two hours. The cause of fire is being investigated.