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Counting down the world's most polluted cities
Annual average PM2.5, 2025 (µg/m³)
Source: IQAir 2025 World Air Quality Report, PM2.5
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Guess the number: micrograms of PM2.5 per m³ in the worst city
0 µg/m³200 µg/m³
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How to read this chart: A long ranked list scrolls past, each row with a bar on one shared scale, and the number one entry is held back until the end. The rank number is the point, and entries next to each other are often nearly tied. More on leaderboard charts.
The takeaway
13 of the 15 most polluted cities are in India or Pakistan.
What the numbers show
IQAir's 2025 World Air Quality Report, published on 24 March 2026, ranked 9,446 cities in 143 countries and territories by annual average PM2.5, the fine particles small enough to reach deep into the lungs. The most polluted was Loni, in Uttar Pradesh, India, at 112.5 µg/m³, up nearly 23% from 2024.
Hotan in China (109.6) came second and Byrnihat in India (101.1) third, with Delhi (99.6) and Faisalabad in Pakistan (98.8) completing the top five. Thirteen of the 15 cities in this countdown are in India or Pakistan; the other two, Hotan and Kashgar, are in China.
For scale, the WHO's annual PM2.5 guideline is 5 µg/m³, so Loni's average is more than 22 times higher. IQAir reports that only 14% of the cities it tracked met that guideline in 2025, down from 17% the year before.
The data
IQAir 2025 World Air Quality Report, PM2.5. IQAir ranks places by the data from their monitoring stations, so coverage differs from city to city. IQAir lists Delhi and New Delhi as separate entries.
| Label | Value | Note |
|---|---|---|
| inLoni | 112.5 µg/m³ | |
| cnHotan | 109.6 µg/m³ | |
| inByrnihat | 101.1 µg/m³ | |
| inDelhi | 99.6 µg/m³ | |
| pkFaisalabad | 98.8 µg/m³ | |
| pkRahim Yar Khan | 92.6 µg/m³ | |
| inGhaziabad | 89.2 µg/m³ | |
| pkLahore | 88.9 µg/m³ | |
| pkSukkur | 88.6 µg/m³ | |
| inUla | 86.8 µg/m³ | |
| pkPattoki | 86.7 µg/m³ | |
| inMullanpur Dhaka | 86.2 µg/m³ | In Punjab, India — not Dhaka |
| pkLodhran | 85.3 µg/m³ | |
| cnKashgar | 84 µg/m³ | |
| inMadhyamgram | 83.3 µg/m³ |
Transcript
112.5 micrograms of PM2.5 per cubic metre. That's the world's worst city. Guess which. The countdown opens in the eighties with Madhyamgram and Lodhran. Then Lahore at 88.9, Delhi at 99.6, and Byrnihat at 101.1. Only two cities are worse, and Hotan, in China, is one of them. Thirteen of the fifteen are in India or Pakistan. Follow for daily stats from NumberReels, and tell us which stat you'd like to see next.
Source & method
- Figures from IQAir 2025 World Air Quality Report, PM2.5.
- Rendered as a leaderboard chart.
- Worth knowing: IQAir ranks places by the data from their monitoring stations, so coverage differs from city to city. IQAir lists Delhi and New Delhi as separate entries.
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