Mumbai Braces for Worsening Air Quality as La Niña Approaches

As of October 15, 2025, Mumbai's overall air quality has taken a concerning turn for the worse. The city's Air Quality Index (AQI) readings, which were in the double digits until October 9, have now surged into triple digits, marking a consistent deterioration in air quality.

While Mumbai's current overall AQI stands at 139, which is considered 'moderate', several pockets of the city have already recorded much worse readings. The Bandra Kurla Complex (BKC) and Deonar areas have registered AQI levels of 221 and 235, respectively, which are classified as 'poor'.

Experts have attributed this rapid decline in air quality to the early onset of La Niña conditions. La Niña, a climate pattern characterized by the cooling of surface-ocean waters in the equatorial Pacific, typically results in reduced wind speeds that prevent pollutants from dispersing quickly. This causes the pollutants to linger longer in the air, particularly in coastal cities like Mumbai.

According to Gufran Beig, chair professor of the National Institute of Atmospheric Sciences (NIAS), the La Niña effect is expected to intensify starting November, leading to cooler temperatures and slower wind speeds. This, in turn, will likely worsen Mumbai's overall AQI as the winter progresses.

The administration has been urged to take proactive measures to address the issue, such as ensuring smooth traffic flow, curbing open burning of garbage, and closely monitoring local-level AQI to better understand the patterns. With the early warning signs, Mumbai residents may be in for a challenging winter ahead as the city grapples with deteriorating air quality.