Beijing Air Quality Deteriorates, ranking Among World’s Most Polluted Cities
BEIJING – Air quality in Beijing sharply declined on september 12, 2025, pushing the city into the “unhealthy” category and ranking it as the 5th most polluted major city globally, according to data from IQAir. The current surge in pollution represents a important deterioration from the 2024 average, were PM2.5 concentrations were 30.9 µg/m³, corresponding to an AQI of 92 (“moderate”). This average was already 6.2 times the World Health Institution’s (WHO) annual guideline of 5 µg/m³.
Today’s AQI has climbed to 147, more than 50% higher than last year’s average, highlighting Beijing’s vulnerability to sudden pollution spikes. While forecasts indicate potential improvement by evening as winds increase, the episode underscores the ongoing challenges to maintaining consistently safe air quality levels in the city.
Beijing’s poor air quality stems from a combination of factors including industrial emissions, coal combustion - notably during heating seasons – vehicle exhaust, and seasonal dust storms originating from the Gobi Desert. Weather conditions, such as thermal inversions, further exacerbate the issue by trapping pollutants near ground level.
Authorities and health officials continue to emphasize the need for sustained, large-scale measures, including stricter emissions controls and a transition to cleaner energy sources, to safeguard public health. Residents are advised to take precautions during periods of poor air quality.
