<p>We examined how social dynamics shape perceptions of urban air quality. Although air quality has improved in several European cities, public perceptions often lag, with many perceiving it as worsening. Drawing on theories of environmental risk perception and a georeferenced survey of residents in Barcelona and Madrid, we used regression models to assess how factors such as population density, income inequality, and sociodemographic characteristics influence perceptions of air quality. We posit that a prevalence-induced concept change may be at play, in which declining pollution levels prompt residents to redefine poor air quality as they become more environmentally aware. This, coupled with social and political influences, creates a misperception that necessitates improved public communication strategies and urban planning that bridges the gap between objective improvements and subjective experiences. By acknowledging the role of social processes in environmental perception, our research underscores the importance of aligning public understanding with policy efforts for effective air quality management in contemporary cities.</p>