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

March 18, 2025

The growing challenge of particulate pollution in Kolkata remains a concern despite improvements in winter air quality. According to a new analysis by the Urban Lab at the Centre for Science and Environment (CSE), Kolkata recorded its lowest winter average PM2.5 level in four years, with a seasonal average of 65 µg/m³—a 19 per cent decline compared to the previous three winters. This assessment, based on winter PM2.5 trends from October 1, 2024, to January 31, 2025, highlights both progress and ongoing pollution hotspots across the city.

While the overall seasonal average has improved, pollution spikes continue to be a challenge. The highest daily PM2.5 level this winter was recorded at 135 µg/m³ on November 2, marking a 6 per cent decrease from past winter peaks. However, localized pollution surges remain significant—Ballygunge recorded the highest daily spike at 195 µg/m³.