Top 25 Cities with Worst Air Quality (2025 AQI Rankings)
Smart Air is dedicated to providing free educational content on the dangers of air pollution and helping people breathe safely. We analyzed data published by the World Air Quality Index project and put together the 2025 updated ranking of the “25 Cities with the Worst Air Pollution in the World”.
Air pollution remains a prevalent health crisis around the world, with many cities recording dangerous levels of air pollution; some over 15 times the recommended annual limit of 5µg/m3 by the World Health Organisation. Studies have found evidence that air pollution levels are positively correlated with the risk of disease from stroke, lung cancer, heart disease, and respiratory diseases.
Data Source: https://aqicn.org/data-platform/covid19/
Scroll down below for the full rundown of the world’s most polluted cities, which countries they’re in, and their annual average PM2.5 levels.
Rankings: 25 Most Air Quality Cities in the World in 2025
1. Islamabad, Pakistan (125.1 µg/m3)
2. Hotan Prefecture, China (115.7 µg/m3)
3. Abu Dhabi, UAE (113.5 µg/m3)
4. Punjabi Bagh, India (99.4 µg/m3)
5. Dwarka, India (98.3 µg/m3)
6. Delhi, India (96.1 µg/m3)
7. Kashgar Prefecture, China (92 µg/m3)
8. Noida, India (91.7 µg/m3)
9. Greater Noida, India (88.8 µg/m3)
10. Bhiwadi, India (82.6 µg/m3)
11. Ghaziabad, India (82.2 µg/m3)
12. Aksu, China (75.7 µg/m3)
13. Lima, Peru (72.5 µg/m3)
14. Lucknow, India (71.1 µg/m3)
15. Hajipur, India (71 µg/m3)
16. Muzaffarnagar, India (68.6 µg/m3)
17. Hapur, India (67.1 µg/m3)
18. Gummidipoondi, India (65 µg/m3)
19. Bulandshahr, India (64.5 µg/m3)
20. Kota, India (64 µg/m3)
21. Talcher, India (63.9 µg/m3)
22. Baghpat, India (63.6 µg/m3)
23. Mandideep, India (63.2 µg/m3)
24. Howrah, India (62.7 µg/m3)
25. Patna, India (62.6 µg/m3)
Read More: The 25 Least Polluted Cities in the World?
Analysis
The majority of cities on the list are from India (18 out of 25 cities, or 72%), followed by China (4 cities, 16%), with Pakistan, the UAE, and Peru each contributing 1 city (4% each). The pollution levels for most cities fall between 60–100 µg/m³, indicating extremely hazardous long-term exposure. A strong regional concentration is visible in the Indo-Gangetic Plain, particularly around Delhi and Uttar Pradesh, while several cities in Xinjiang, China also appear due to a mix of desert dust and local emissions. Overall, the data shows that the world’s highest PM2.5 concentrations are heavily concentrated in South Asia, with annual averages that are 12–25 times above the WHO annual guideline of 5 µg/m³.
Read More: 20 Most Polluted Cities in India (2023 Rankings)
Data bias
Africa and South America have fewer public air quality monitoring stations, so it is difficult to know the pollution levels on the ground in these regions.
The fact that so many Indian cities are featured on the list is a testament to the fact that they have large and wide air pollution monitoring networks set up to detect pollution levels.
How Air Pollution Was Measured to Find the Most Polluted Cities in the World
These rankings of the 2025 most polluted cities in the world use data on average PM2.5 pollution levels from the 12 months before the publication date.
These small particles 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.
Open Data
The PM2.5 AQI 2025 world pollution data used for the rankings of the world’s worst polluted cities are openly available. To download the complete raw data, visit https://aqicn.org/data-platform/covid19/.
Watch: Run Down of Top 5 Most Polluted Cities in the World in 2022
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