Bangkok air warning: Residents must wear masks due to unhealthy dust
Bangkok Metropolitan Administration warns residents to wear face masks and limit strenuous outdoor activity due to unhealthy air quality.
- Bangkok has issued an air quality warning as PM2.5 dust levels have exceeded the safety standard, reaching a level classified as unhealthy.
- Officials are advising all residents to wear protective masks when outdoors and to limit strenuous activities due to the health risks.
- The poor air quality is attributed to a combination of weather conditions trapping pollutants and smoke from agricultural burning in surrounding regions.
- The unhealthy conditions are expected to persist until approximately December 2, with air quality forecast to improve the following week.
Narong Rueangsri, Deputy Permanent Secretary for the Bangkok Metropolitan Administration (BMA), disclosed that the Bangkok Air Quality Data Centre reported the situation of Particulate Matter 2.5 (PM2.5) in Bangkok as of 11am on November 30, 2025.
The average PM2.5 level across Bangkok is 42.6 µg/m³ (micrograms per cubic meter), which is higher than the standard set at 37.5 µg/m³. This places the overall air quality in the "Orange" category, meaning it is starting to affect health.
The PM2.5 levels in the Bangkok Metropolitan Region are forecast to exceed the standard until approximately December 2, 2025. Therefore, the public is advised to take care of their health, with the following recommendations:
Air Quality Level: Orange (Starting to Affect Health)
General Population:
- Use personal protective equipment such as PM2.5 protective masks every time you go outdoors.
- Limit the duration of strenuous outdoor activities or exercise.
- Be vigilant for abnormal symptoms such as coughing, difficulty breathing, or eye irritation.
Vulnerable Groups (Children, the Elderly, Pregnant Women, People with Underlying Health Conditions):
- Use personal protective equipment such as PM2.5 protective masks every time you go outdoors.
- Avoid strenuous outdoor activities or exercise.
- Follow the advice of a doctor.
- Seek immediate medical attention if any abnormal symptoms occur.
The overall meteorological conditions, with a strong high-pressure system from China covering Thailand, have resulted in cooler air over Bangkok.
This leads to a high chance of an inversion condition and a reduced mixing layer height, which results in poor ventilation and a tendency for dust accumulation in some areas exceeding the standard.
Furthermore, during the dry weather and the end of the harvest season, a continuous increase in hotspots (burning biomass) has been detected in the Central and Northeastern regions, as well as in the provinces surrounding Bangkok (upwind areas to the north and northeast).
Hotspots from the burning of biomass residue in these upwind areas can transport dust and contribute to its accumulation in Bangkok, resulting in air quality exceeding the standard during this period.
It is expected that the ventilation will improve next week, between December 3-5, 2025, and PM2.5 levels are likely to decrease.
