Delhi air quality plunged to its worst post-Diwali levels in five years, with PM2.5 levels soaring to an alarming 488 µg/m³ a 212% spike from pre-Diwali figures. A new analysis by research group Climate Trends revealed that this surge was driven largely by firecracker emissions, even though stubble burning in Punjab and Haryana fell sharply this year.
The report, based on Central Pollution Control Board (CPCB) data, shows that Punjab and Haryana recorded only 175 farm fire incidents between October 1 and 12, compared to 779 in the same period last year a 77.5% decline caused mainly by flood-induced delays in paddy harvesting. Yet, Delhi’s AQI dipped into the ‘severe’ category as thick smog engulfed the city on Tuesday morning.
Experts from Climate Trends said that the 2025 Diwali was among the most polluted in recent years, with pollution levels tripling overnight. Research Lead Palak Balyan noted that PM2.5 levels jumped from 156.6 µg/m³ before Diwali to nearly 488 µg/m³ after the festival, with peak concentrations touching 675 µg/m³ late at night on October 20. “This year’s Diwali clearly shows that cracker emissions remain the single biggest factor behind Delhi’s pollution spike,” she said.
The report also points to low wind speeds (below 1 m/s) and a sudden temperature drop (from 27°C to 19°C) as key factors that trapped pollutants in the atmosphere. Experts from Delhi University confirmed that the smog was locally generated, ruling out long-distance pollution transport due to stagnant wind patterns.
The findings have reignited the political blame game over Delhi’s pollution crisis. Environment Minister Manjinder Singh Sirsa accused the Aam Aadmi Party of failing to prevent crop residue burning in Punjab, while AAP leaders, including Saurabh Bharadwaj, criticized the government for allowing widespread firecracker use despite a two-hour restriction on ‘green’ crackers.
The Supreme Court had permitted the sale and bursting of green crackers in the Delhi-NCR region between October 18 and 21. However, environmental experts said that visuals and air quality data showed no measurable difference between green and conventional firecrackers.
Meteorologists also highlighted that wind stagnation and high humidity levels ranging from 60% to 90% across Delhi intensified the smog. “The pollution spike is local, not imported. Even so-called green crackers increased particulate matter rapidly. We must urgently check their quality and chemical composition,” said Dr. S.K. Dhaka of Rajdhani College.
The Climate Trends report concluded that while reducing stubble burning is essential for long-term air quality gains, immediate post-Diwali pollution spikes will persist unless firecracker emissions are tightly controlled.
With Delhi now recording its highest post-Diwali PM2.5 levels since 2020, experts warn that stricter enforcement, public awareness, and consistent year-round emission control not just seasonal bans are crucial to prevent the capital from choking every festive season.