Smoke from Punjab and Haryana farm fires drives Delhi air pollution
Delhi's air quality index reached the very poor category on Monday as smoke from evening crop fires moved into the capital.
Delhi's Air Quality Index (AQI) hit 324 by 4 PM on Monday, crossing the 300-mark threshold for the very poor category for the first time this season, according to an analysis by HT reported by Mint.
The surge follows an increase from an AQI of 117 on Saturday to 261 on Sunday. On the night of November 1, PM2.5 levels averaged 194 micrograms per cubic metre, which is more than three times the Indian safe limit of 60.
The analysis indicates that smoke from evening farm fires in Punjab and Haryana was the primary driver of the deterioration. While stagnant weather played a role, meteorological factors alone do not explain the spike, as similar conditions on October 18 and 28 resulted in cleaner air.
A shift in crop-burning patterns was noted, with a 2025 report by the research group iFOREST stating that over 90% of large fires in Punjab during 2024 and 2025 were lit after 3 PM. This is a significant increase from 3% in 2021.
Data from the INSAT-3DS satellite showed evening fire counts rose from 17 on October 29 to 90 on November 1. On the afternoon of November 1, winds blew directly from the northwest fire belt, carrying air that had spent most of its time over Punjab and Haryana.
The composition of the air on the night of November 1 showed that fine particles, characteristic of smoke, made up nearly 60% of the total particulate matter by weight.