The surge puts the metropolis on track for its sharpest deterioration in air quality during the post-monsoon transition since at least 2019. By Azman Usmani Mumbai residents endured unusually hazy skies for much of October, exposing the limits of coastal winds that have long shielded India’s financial capital from the severe air pollution that plagues cities further north. The city’s average daily air quality index more than doubled to 102 through Oct.