2021 world air quality report

This 2021 World Air Quality Report presents an overview of the state of global air quality in 2021. The report is based on PM2.5 air quality data from 6,475 cities in 117 countries, regions and territories around the world. The data used to create this report was generated by tens of thousands of regulatory and low-cost air quality monitoring stations operated by governments, non-profit organizations, research institutions, educational facilities, companies, and citizen scientists around the world.

The PM2.5 data presented here is reported in units of micrograms per cubic meter (µg/m³) and utilizes the latest World Health Organization (WHO) annual PM2.5 air quality guideline and interim targets as a framework for data visualization.

The dataset used to generate this report was derived from the IQAir real-time online air quality monitoring platform, which aggregates, validates, calibrates, and harmonizes data from air quality monitoring stations around the globe.

Additional information on real-time and historic air quality conditions in cities, countries, and regions around the world is available on the IQAir website, with a ranking of annual air quality data for 6,475 cities and an interactive global map of annual city concentrations.

With these resources, IQAir endeavors to engage, educate, and inspire governments, researchers, NGOs, companies, and citizens to work together to improve air quality and create healthier communities and cities.