A total of 74 flights to and from Chiang Mai will be cancelled during the three-day Yi Peng, or Loy Krathong, festival next week to prevent possible accidents involving floating lanterns.
Of the cancelled flights, 62 are domestic services and 12 are international.
Another 41 flights, both domestic and international, will be rescheduled. Two more flights will be added.
The flight changes affect travel from next Tuesday to Thursday
Capt Wisoot Chantana, director of Chiang Mai international airport, said there are normally about 180 flights through the airport each day, for a total of 20,000 passengers. The daily number of passengers rose to around 25,000 during the festive season.
For next week's Loy Krathong festival, Chiang Mai province has announced set times for the releasing of floating lanterns in five districts -- Muang, Hang Dong, Saraphi, Mae Rim and San Sai. People in these districts can celebrate the festival on Loy Krathong day next Thursday, with smoke lanterns from 10am to noon and burning floating lanterns after 9pm.
The airport has informed airlines of the regulation and they had requested changes to flight schedules during the period Nov 24-26.
For domestic travel, Thai AirAsia cancelled 24 flights between Bangkok and Chiang Mai, and six flights each between Chiang Mai and Phuket and Chiang Mai and Krabi.
Thai Lion air cancelled six flights and Bangkok Airways eight flights between Bangkok and Chiang Mai.
A total of 62 domestic flights with 9,300 passenger seats have been cancelled during the period.
Another 21 flights with 3,150 passenger seats have been rescheduled.
However, Thai Smile has added two more flights between Suvarnabhumi and Chiang Mai on Nov 26.
For international travel, four airlines serving Chiang Mai and cities in China will cancel 12 flights with 1,800 passengers during the period.
Four airlines serving Chiang Mai and cities in China and Hong Kong rescheduled 20 flights with 3,000 passengers.
Cap Wisoot said travellers should check flight schedules with their airlines again, as the airlines had changed the flight times quite often based on safety concerns.
He said the airport would increase safety inspections of the runway to 10 times a day from the normal four.