Winter pollution crisis in megacities of India: Going beyond Delhi Mumbai

March 18, 2025

The growing problem of particulate pollution in Mumbai has once again come into focus this winter. According to a new analysis by the Urban Lab at the Centre for Science and Environment (CSE), Mumbai recorded its lowest winter average PM2.5 level in four years, with a seasonal average of 49 µg/m³—a 24 per cent decline compared to previous winters. This assessment, based on winter PM2.5 trends from October 1, 2024, to January 31, 2025, highlights both progress and persistent challenges in air quality management across the region.

While the overall seasonal average has improved, the problem of winter pollution remains widespread, affecting both large cities and smaller towns. The highest daily PM2.5 level this winter was 81 µg/m³, marking a 44% decline from past peaks. However, localized pollution spikes remain concerning—MaladW (IITM) recorded the highest daily surge of 194 µg/m³. Despite seasonal improvements, winter pollution levels across many locations exceeded annual averages. Deonar emerged as the most polluted area, with a winter average PM2.5 level of 80 µg/m³, followed by Shivaji Nagar at 76 µg/m³.