Live · world air quality
Across the world cities we track, air averages US AQI 78 right now.
World Air Quality Index (AQI) Today
Live air quality for major world cities on the US EPA scale — 46 reporting now, updated hourly from OpenAQ station data.
Right now the most polluted world city we track is Gujranwala (US AQI 343, Hazardous).
World cities by current AQI
About the world air quality index
This page brings together live air quality for major cities worldwide, reported on the US EPA AQI scale so the numbers are comparable across countries. Air pollution is a global problem — from the winter smog of South Asia to seasonal wildfire haze elsewhere — and the index turns a set of pollutant measurements into a single 0–500 number with a colour and a health message. Open any city for its live reading, pollutant breakdown and a plain-English "is it safe to go out?" answer. For Indian cities, see our India air quality index, which uses the national CPCB scale.
Frequently asked questions
Which world city has the worst air quality today?
Among the world cities we track, Gujranwala currently has the highest US AQI at 343 (Hazardous).
What AQI scale do world cities use?
The US EPA AQI scale (0–500) — the global standard used by most international air-quality services — computed from PM2.5 and PM10. Indian cities use India's CPCB scale.
Where does the data come from?
Public monitoring stations aggregated by OpenAQ. We show a city only when it has a station reading from the last few hours.