The hazardous haze has affected health in five districts -- Prawet, Khlong San, Bangkok Yai, Nongkhaem, Bang Bon.
The IQAir website for air relegated Bangkok to the 10th most polluted city at 10.10am.
Teerapat Prayoonsit, permanent secretary at the Prime Minister's Office, said that the haze would further cover Bangkok until December 17.
He said that factors such as wind and depression cause the air to be still and the dust from vehicle combustion keeps circulating in the capital.