World Cities Day

What are the top 5 cleanest cities and top 5 most polluted cities according to our data?
In honour of World Cities Day (31 October) and the World Health Organisation, we’re sharing some fresh insights from our latest AirTrack data, highlighting the top five cleanest cities and the top five where air pollution remains a major challenge.
According to WHO data, only 17% of cities worldwide meet the annual fine particulate matter (PM2.5) guideline — meaning most of us are still breathing air that isn’t as clean as it should be.From the launch of AirTrack through to the end of September 2025 our data shows that both Australia and the Netherlands appear at both ends of the spectrum — home to some of the cleanest air, but also among the highest recorded nitrogen dioxide (NO2) levels.
It’s a reminder that air quality isn’t static — it shifts with time, weather, traffic, and local action.💡 World Cities Day is a reminder that better data means better cities.
At Air Aware Labs, we’re making that data accessible so citizens, planners and policymakers can act together for change.




