Capital city in Tehran Province, Iran
Air quality in Tehran
Very polluted
The annual average PM2.5 in Tehran was 31 µg/m³ in 2020, about 6.2 times the WHO guideline of 5 µg/m³. Temperature inversions trap traffic smog, making Tehran among the most polluted cities from autumn to winter; schools and offices sometimes close.
Key facts
- PM2.5: 31 µg/m³ yearly average (2020). Measured at Tehran.
- Worst months: Oct–Jan.
- Recent average: 28.8 µg/m³ over the last five years of measurements.
PM2.5 by year
| Year | Annual average |
|---|---|
| 2020 | |
| 2019 | |
| 2018 | |
| 2016 | |
| 2015 | |
| 2014 |
Air quality across Iran
Quick answers
Is the air in Tehran bad?
Very polluted: 31 µg/m³ of PM2.5 on average, 6.2× the WHO guideline. It's usually worst in Oct–Jan.
When is the air worst in Tehran?
Temperature inversions trap traffic smog, making Tehran among the most polluted cities from autumn to winter; schools and offices sometimes close.
How does Tehran compare with the rest of Iran?
People in Iran breathe 40 µg/m³ of PM2.5 on average (2023, World Bank/WHO), against 31 µg/m³ measured here.
More about Tehran
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Sources
- WHO Ambient Air Quality Database
- WHO air quality guidelines (2021)
- Live air quality map (WAQI)
- Iran e-visa portal
- UK FCDO travel advice: Iran
Annual averages are measured values reported to the WHO; check a live map for today's air. Compiled and reviewed by SoloSquare. How we compile and score this. Spotted something out of date? Tell us.