Bangkok’s air quality has deteriorated, with PM2.5 levels rising above safe standards, according to an update from the Bangkok Air Quality Data Centre on Sunday.
Narong Rueangsri, Deputy Permanent Secretary of the Bangkok Metropolitan Administration (BMA), confirmed that as of 11am on November 30, 2025, pollution levels had reached concerning levels across the capital.
The average PM2.5 concentration currently stands at 42.6 µg/m³, exceeding the national standard of 37.5 µg/m³. This places Bangkok in the “Orange” air quality category, signalling that health impacts have begun.
Forecasts indicate that PM2.5 levels will remain above the safety threshold until around December 2, prompting authorities to advise the public to take protective measures.
Residents are urged to wear PM2.5 protective masks whenever outdoors. Those engaging in outdoor exercise are advised to limit duration and intensity, and to stay alert for symptoms such as persistent coughing, breathing difficulties, or eye irritation.
Vulnerable groups — including children, pregnant women, the elderly, and individuals with underlying health conditions — are encouraged to avoid strenuous outdoor activity altogether and seek medical attention if any abnormal symptoms arise.
A strong high-pressure system from China has brought cooler air over Bangkok, increasing the likelihood of temperature inversion, a phenomenon that traps polluted air closer to the ground.
This has reduced the mixing layer height and impaired air circulation, allowing dust and fine particulates to accumulate in several areas above standard levels.
The dry season and the end of the harvest period have led to a rise in hotspots from biomass burning in the Central and Northeastern regions.
Provinces surrounding Bangkok, particularly those situated upwind to the north and northeast, have also recorded increased burning activity.
According to the centre, airborne particles from these hotspots may be carried into the capital, further worsening air quality.
Authorities expect ventilation to improve between December 3 and 5, which should help reduce PM2.5 concentrations. Until then, residents are advised to monitor air quality reports closely and exercise caution when outdoors.
