Air Pollution in Thailand: Bangkok and 20 Provinces on Red Alert for PM2.5
Written by the editors of theo-courant.com, your reference guide to Thailand and South-East Asia - based in Bangkok, at the heart of Thai culture.
Bangkok and a large part of Thailand are experiencing another severe air pollution episode, with PM2.5 levels well above official health thresholds. For travelers, this situation calls for vigilance, itinerary adjustments, and daily monitoring of air quality.
Dense smog over Bangkok and the central region
On Wednesday morning, a thick smog blanketed Bangkok. Data released at 7 a.m. by Thailand’s Geo-Informatics and Space Technology Development Agency (Gistda) showed red-level concentrations — considered seriously harmful — of fine PM2.5 particles in the capital and 20 provinces. Nationwide, 54 provinces recorded air pollution levels classified as dangerous to health.
Measured concentrations ranged from 79.2 to 108 µg/m³, while the safety threshold set by the Thai government is 37.5 µg/m³. In practical terms, this means that in several areas, pollution levels were close to three times higher than the official limit.
The most affected areas around Bangkok
Unsurprisingly, the highest readings were recorded in the industrial and densely populated provinces surrounding Bangkok. Samut Sakhon topped the list with 108 µg/m³, followed by Nakhon Pathom (102.1 µg/m³) and Nonthaburi (101.1 µg/m³). Bangkok itself followed closely at 98.5 µg/m³, ahead of Samut Songkhram and Pathum Thani.
Other central and eastern provinces — including Ayutthaya, Samut Prakan, Chon Buri, and Kanchanaburi — were also classified in the red zone, confirming that this episode extends far beyond the capital and affects a major economic and tourist area.
Concerning pollution levels across much of the country
Beyond the red zones, many provinces were ranked orange, with PM2.5 levels between 39 and 74.9 µg/m³, posing clear health risks, especially for sensitive individuals. This included parts of the Northeast (Khon Kaen, Udon Thani, Nong Khai), the eastern seaboard (Rayong, Chanthaburi, Trat), and even the tourist-heavy South, including Phuket.
By contrast, only a handful of provinces enjoyed good to very good air quality, such as Chiang Mai, Chiang Rai, and Mae Hong Son, the latter recording particularly low PM2.5 levels at 12.9 µg/m³.
7-day air pollution forecast in Thailand (Bangkok and central region)
According to IQAir’s weekly forecasts, PM2.5 levels are expected to remain high to very high in Bangkok and surrounding provinces over the coming days.
Forecast models point to stagnant air conditions until midweek, with Air Quality Index (AQI) values fluctuating between Unhealthy for Sensitive Groups and Unhealthy. A gradual improvement may occur toward the end of the week, depending on a slight increase in winds from the Gulf of Thailand.
In concrete terms, PM2.5 concentrations are likely to stay above 70 µg/m³, with possible peaks approaching or exceeding 100 µg/m³ during calm mornings. Such levels remain incompatible with prolonged outdoor tourist activities, particularly in Bangkok, Nonthaburi, Samut Sakhon, and Nakhon Pathom.
Sources and real-time monitoring:
- IQAir – Air Quality Forecast for Thailand and Bangkok
- AQICN – World Air Quality Map (hourly data and short-term forecasts)
Travelers are strongly advised to consult these platforms daily, as forecasts can change quickly depending on wind and weather conditions.
What this means in practical terms for travelers
For visitors, these pollution episodes are far from trivial. Prolonged exposure to PM2.5 can cause irritation, coughing, fatigue, headaches, and may worsen respiratory or cardiovascular conditions. In the short term, it can turn an urban stay or beach holiday into an uncomfortable experience.
During periods of high pollution, travelers should limit outdoor activities, avoid sustained physical exertion, and wear a certified N95 (or equivalent) mask when moving around. Sensitive groups — children, older adults, and people with asthma — should take extra precautions and consider destinations less exposed to pollution, particularly in the southern peninsula or mountainous regions.
How to track air pollution in Thailand
Several tools allow travelers to monitor air quality in real time. Official data from Gistda provide a nationwide overview, while independent platforms such as IQAir and AQICN offer detailed maps, multi-day forecasts, and alerts useful for adjusting travel plans or postponing excursions.
For travelers, checking air quality has become almost as essential as checking the weather before booking accommodation or planning visits.
A political issue downplayed despite its impact on tourism
In conclusion, this episode once again raises a persistent question in Thailand: the lack of sustained political commitment to tackling air pollution. Despite repeated warnings, measures remain temporary, often symbolic, and rarely structural. No major political party appears to place air quality at the core of its agenda.
Yet the link with a decline in tourist appeal is becoming increasingly clear. Bangkok chokes for several weeks each year, Phuket now appears on global pollution maps, and some travelers actively avoid Thailand during the dry season. In the long run, ignoring this environmental issue may prove far more costly than investing seriously in long-term solutions.
