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Global Cities Fail Air Quality Test: Only 14% Meet WHO Standards
25 Mar
Summary
- Only 14% of global cities met World Health Organization air pollution guidelines in 2025.
- Wildfire smoke significantly degraded air quality in North America and globally.
- The US ranked 24th out of 143 countries for air quality, with cleaner air than most.
In 2025, a concerning global trend emerged as air quality deteriorated, with only 14% of cities worldwide meeting the World Health Organization's air pollution guidelines. This marks a decline from the previous year. Analysis of data from over 9,000 cities indicated that just 9% achieved recommended air quality levels.
The United States, however, demonstrated significantly better average air quality compared to many nations, securing 24th place out of 143 countries. This suggests an improving national trend, despite localized issues.
Wildfire smoke played a major role in degrading air quality. Smoke from Canadian wildfires caused New York City to experience the ninth-worst air quality globally on certain days in August 2025. Canada was identified as the most polluted country in North America for the year.
In the U.S., the Los Angeles region suffered the worst air quality, with averages exceeding 14. This was partly attributed to extensive wildfires in Southern California in January 2025, which burned thousands of acres and affected millions.
Experts emphasize that chronic exposure to air pollution, often containing microscopic particles from sources like vehicle exhaust and wildfires, poses serious health risks, including respiratory problems and increased mortality. The WHO has classified air pollution as carcinogenic.
