Rung Hiranwong, chief of the Doi Inthanon National Park, said the country’s highest mountain was more crowded than normal due to it being a public holiday.
He said the lowest temperature on the mountain was 8C, while the viewpoint at Kiew Mae Parn fell to 9C.
The park had 11,189 visitors on Sunday, 418 of them foreigners, while a total of 3,400 vehicles visited during the day.
He advised tourists to check that their vehicles were in good working order before climbing up the mountain, especially their fog lights, saying the morning fog was always thick, leading to poor visibility.