Looking to find the most polluted cities in Thailand? Smart Air analyzed 2023 air pollution data for dozens of Thailand cities to generate the 2023 ranking of the “10 Most Polluted Cities in Thailand”.

Scroll down for the full rundown of the most polluted cities in Thailand and their annual PM2.5 levels. and their annual PM2.5 levels. The annual average PM2.5 in micrograms (µg/m3) is also given. For reference, the WHO recommended annual limit is 5 micrograms.

Rankings: 10 Most Polluted Cities in Thailand

The rankings for the least polluted cities in Thailand are based on PM2.5 air pollution data from the 12 months prior to the publication date.

1. Si Sa Ket (79.5 µg/m3)

Si Sa Ket, one of most polluted cities in Thailand 2023

2. Chiang Rai (76.7 µg/m3)

Chiang Rai, one of most polluted cities in Thailand 2023

3. Lampang (74 µg/m3)

Lampang, one of most polluted cities in Thailand 2023

4. Phetchabun (69.2 µg/m3)

Phetchabun, one of most polluted cities in Thailand 2023

5. Phitsanulok (69.2 µg/m3)

Phitsanulok, one of most polluted cities in Thailand 2023

6. Chiang Mai (64.8 µg/m3)

Chiang Mai, one of most polluted cities in Thailand 2023

7. Uttaradit (54.4 µg/m3)

Uttaradit, one of most polluted cities in Thailand 2023

8. Phetchaburi (46.5 µg/m3)

Phetchaburi, one of most polluted cities in Thailand 2023

9. Ratchaburi (46.5 µg/m3)

Ratchaburi, one of most polluted cities in Thailand 2023

10. Maha Sarakham (45.2 µg/m3)

Maha Sarakham, one of most polluted cities in Thailand 2023

There is research that even little amounts of pollution such as those typically present in these least polluted cities can have an impact on health.

Below is a pollution heat map from the WHO. WHO research shows that over 99% of people in the world are breathing unsafe air with high air pollution levels.

How Air Pollution Was Measured to Find Least Polluted Cities in Thailand

The above rankings of the 2023 least polluted Thailand were ranked based on their average PM_2.5 pollution levels from the 12 months prior to the publication date.

These small pollutants are under 2.5 micrograms in width and are considered to be one of the more dangerous pollutants due to their ability to enter deep into the lungs and bloodstream.

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