Why does Melbourne usually avoid the severe air pollution found in some large cities?

Melbourne typically avoids the severe air pollution experienced by other large cities due to its specific weather patterns. The city's climate is characterized by the eastward flow of high-pressure cells separated by low-pressure troughs.1

The winds associated with the consistent passage of these weather systems play a crucial role in maintaining air quality. These winds facilitate the horizontal dilution and dispersion of pollutants, preventing the accumulation that often occurs in areas with more stable atmospheric conditions or geographic features that trap air. Unlike cities surrounded by mountains that block horizontal air motion, Melbourne’s atmospheric environment benefits from these active weather systems, which help ensure that pollutants do not stagnate near the ground.12