BANGKOK, March 5, 2025 (BSS/AFP) - One of Thailand's main airlines is suspending flights between Bangkok and a northern province for more than a month because of poor visibility caused by air pollution, the carrier confirmed on Wednesday.

Air pollution spikes in Thailand, especially in the north, between December and April as farmers burn stubble to prepare land for the next crop season.

Domestic carrier Bangkok Airways is halting flights from Bangkok to the northwestern town of Mae Hong Son because smog was expected to make visibility too poor to land, an airline official told AFP.

"We experienced the same problem last year when smog levels were extremely high," the Bangkok Airways official at Mae Hong Son airport said.

The airport authority in Mae Hong Son, a popular stop on the backpacker trail in northern Thailand, announced on Facebook last week that flights would be suspended from March 15 to April 20.

"Smog affects vision and safety of the airlines," the post said.

The air quality index for Mae Hong Son was 7.9 times greater than World Health Organization guidelines, according to IQ Air data, which measures global air pollution. 

Thailand has become increasingly alarmed about the effects of air pollution, which causes millions of people to need medical treatment each year.

The government banned crop burning early this year, with violators facing fines and legal action, although it is not yet clear what impact the measures are having.

The Department of National Disaster Prevention and Mitigation was ordered to "update the actual situation to restore confidence among business operators", the government said in a statement after the Bangkok Airways flight suspension.