Tehran’s air quality worsens with fewer clean days in 2025

This marks a drop from the already low figure of 10 clean air days in 2023, meaning residents had to wait on average 52 days for a single day of breathable, pollutant-free air.

Once considered a rare respite, clean air in the Iranian capital has become even more elusive.

Experts have long warned about the dangerous health effects of prolonged exposure to high pollution levels, especially for vulnerable groups such as children, the elderly, and individuals with respiratory conditions.

The worsening situation forced authorities to take emergency measures several times throughout the year. On multiple occasions, schools, government offices, and even some industrial activities were suspended to mitigate the effects of smog and reduce pollutant output. These closures, which often lasted for days, came in response to dangerously high concentrations of fine particulate matter and other harmful pollutants.

Tehran, with its heavy traffic congestion, industrial activity, and geographical layout that traps air masses, continues to rank among the world’s most polluted capitals.

While various policies have been proposed to improve air quality—including traffic restrictions and promotion of cleaner fuels—many experts believe that more aggressive, long-term solutions are needed to address the root causes of the city’s chronic pollution problem.