The smog blanketing much of the North is disrupting flights and seriously reducing the number of tourists travelling to the region, the transport minister said on Tuesday.
Arkhom Termpittayapaisith said the thick fine dust was in particular interrupting air services in Chiang Mai, Chiang Rai and Mae Hong Son provinces.
Since Feb 23, 40 of 400 scheduled flights at Mae Hong Son airport had been cancelled, 28 of them Bangkok Airways flights. At other northern airports, flights were delayed 15-20 minutes and some flights were diverted, the minister said.
Mae Hong Son airport was surrounded by mountains and vulnerable to smoke haze settling there. Chiang Rai and Chiang Mai airports, however, had instrument landing support, Mr Arkhom said.
Somnuek Rongthong, president of Aeronautical Radio of Thailand, said flights were delayed almost daily at Mae Hong Son airport, just as smog also delayed flights in Hanoi.
Suthirawat Suwanawat, general manager of Suvarnabhumi airport, said there were fewer flights from Suvarnabhumi and Don Mueang airports to the North. The number of tourists flying to the North for Songkran was expected to drop to 195,000, compared with 203,000 during the New Year festival.
In March 170,000 tourists flew to the North, down 15% on the previous month, he said.