Why does winter fog and traffic smog affect Milan?

Winter fog and traffic smog are persistent issues in Milan due to a combination of geographical and urban factors.

Winter Fog

Milan’s location in the Po Basin makes it naturally prone to heavy fog during the winter months. While the closure of heavy industry and the removal of nearby rice fields have reduced this phenomenon, it remains a characteristic feature of the local climate.1

Traffic Smog

The city's air quality is significantly impacted by traffic-related air pollution. Despite the availability of mass transit, Milan experiences high rates of private car ownership, which has led to chronic traffic congestion and increased pollution levels since the early 1980s.2

This pollution is exacerbated by the city's urban development: the growth of an almost uninterrupted built-up area around Milan restricts local air circulation, trapping pollutants and preventing them from dispersing. Consequently, local government officials have occasionally been forced to implement bans on private traffic to mitigate these smog levels.12