The timing of stubble burning in Punjab has become the central question in this season's farm-fire debate. An analysis by Hindustan Times, based on air-quality readings, weather observations and satellite data, found that several farm fires were started during the evening, potentially escaping detection by NASA's satellite during its routine afternoon pass. That satellite generally passes over Punjab at around 1.30 pm, and India's standard stubble-fire count rests on its data.

According to iFOREST's Stubble Burning Status Report 2025, more than 90 per cent of large fires in Punjab during 2024 and 2025 were started after 3 pm. India's INSAT-3DS satellite, which monitors the same area throughout the day, recorded evening fires rising from 17 on October 29 to 90 on November 1, while NASA's own count also reached 171 on November 1, its highest of the season at that point. A separate Mirror Now report, based on a tour of districts including Amritsar and Jalandhar, said farmers are increasingly lighting fires after 5 pm, and that US polar-orbiting satellites pass at 10.30 am, 1.30 pm and 1.30 am — leaving a window of about 12 hours with no satellite observation.

The effect showed up in Delhi's air. Between 10 pm on November 1 and 6 am on November 2, Delhi's average PM2.5 concentration reached 194 micrograms per cubic metre, more than three times India's prescribed daily limit of 60, the analysis found. Delhi's AQI rose from 117 on Saturday to 261 on Sunday and 324 by 4 pm on Monday. Weather-balloon observations showed transport-level winds from the north-west on October 31 and November 1, carrying air from the stubble-burning regions of Punjab and Haryana towards Delhi. The analysis itself cautioned that it could not establish the exact contribution of stubble burning to Delhi's spike, and that high humidity following rainfall may also have contributed.

Farmer leaders responded in different ways. Sarwan Singh Pandher of the Punjab Kisan Mazdoor Sangharsh Committee claimed that some village sarpanches have advised farmers to burn quietly during the evening to avoid scrutiny — a claim reported here as his statement, not as an established fact. Manjit Singh Rai, president of the BKU Doaba union, said the focus on satellite detection feels disproportionate, arguing that the same technology does not support farmers when natural disasters such as hail destroy crops. An agriculture department official in Jalandhar, speaking to Mirror Now on condition of anonymity, said the risk of penalties is lower in the evening because most officials have finished their field inspections by then.

The implication is direct: the official daily counts — on which the political argument between Punjab and Delhi turns — may not capture the full scale of burning. A lower count can mean fewer fires, or fires moved to a different hour; the two need to be separated before either government claims the numbers prove its case.