Delhi Records Third-Worst Post-Diwali Pollution Since 2021 as Monitoring Gaps Cloud Full Impact

The situation was further complicated by widespread data outages at air quality monitoring stations across the national capital during the most critical hours of the night.

More than half of the CPCB monitoring stations reportedly stopped transmitting real-time data around midnight as pollution levels began to surge.

Despite the missing data, readings from operational stations painted a grim picture.

A majority of the functioning monitoring stations recorded PM2.5 concentrations within the “Severe” category during the overnight period, indicating extremely hazardous air quality conditions for residents.

Analysts comparing post-Diwali pollution trends over recent years found that Delhi’s pollution spike ranked behind only 2021 and 2025, making it the third-worst post-Diwali air quality event since 2021.

Environmental experts noted that weather conditions likely prevented pollution levels from deteriorating even further.

Relatively warmer nighttime temperatures and moderate winds after midnight helped disperse pollutants, limiting their accumulation across the city.

The latest findings have renewed concerns over the effectiveness of firecracker restrictions and the city’s preparedness to deal with seasonal pollution spikes.

Air quality remains a major public health challenge in Delhi, particularly during the winter months when meteorological conditions often worsen pollution levels.

While the exact extent of the post-Diwali pollution episode may never be fully known due to the monitoring disruptions, the available data clearly indicate that Delhi experienced one of its most polluted festive nights in recent years.