Following the Diwali festival, New Delhi experienced a severe spike in air pollution, with PM2.5 levels exceeding World Health Organization guidelines by over 40 times, making it the world’s most polluted city on October 22, 2025.
On the morning of October 22, residents awoke to a thick smog that blanketed the city, reducing visibility and prompting health advisories. The air quality index reached ‘very poor’ levels, with PM2.5 concentrations peaking at 994 micrograms per cubic meter at midnight on Diwali, far above the safe limit of 60, according to data from IQAir and India’s National Air Quality monitoring.
The primary cause of this deterioration was the widespread use of firecrackers during the festival. Despite a Supreme Court ruling allowing only ‘green’ firecrackers within specific hours, poor enforcement led to extended use and the availability of more polluting traditional crackers. Research from Climate Trends indicated a threefold increase in PM2.5 levels post-Diwali compared to pre-festival readings, highlighting the ineffectiveness of current measures.
Local residents shared their struggles, with many reporting respiratory issues and eye irritation. Anushka Singh, a graphic designer, expressed frustration over the lack of strict implementation of rules, while store owner Chandra Tandon emphasized the need for collective responsibility to reduce the impact.
New Delhi’s air pollution is a chronic issue exacerbated by multiple sources, including vehicular emissions and agricultural burning in neighboring states. Interestingly, farm fires were down by 77% this year, yet the post-Diwali spike was severe, underscoring the dominant role of festival-related activities.
Government initiatives, such as anti-smog guns and traffic rotation schemes, have shown limited success due to inconsistent enforcement. The construction of smog towers has not significantly improved air quality, pointing to the need for more comprehensive and coordinated strategies.
The pollution crisis extends beyond New Delhi, with other Indian cities like Kolkata and Mumbai also ranking among the world’s most polluted. This regional challenge calls for urgent action to address environmental health risks and balance economic development with public well-being.
Moving forward, stronger regulatory frameworks, enhanced public awareness, and better enforcement of existing laws are essential to protect residents from the hazardous air and improve quality of life in the capital.