The season of poor air quality has begun in North India, with experts cautioning against complacency despite Delhi's currently clean air. While the capital's air quality remains moderate, historical trends indicate a significant decline as winter approaches, primarily due to stubble burning in neighboring states.

Stubble burning has commenced, with 64 farm fires already recorded in states near Delhi. Although the impact on Delhi's air quality is currently negligible, patterns from previous years suggest that crop burning intensifies around October, following the monsoon's retreat from northwest India. Of the fires recorded between September 15 and 21, Punjab reported 56 cases, Haryana three, Uttar Pradesh four, and Rajasthan one. Despite recent floods, Punjab has recorded marginally more farm fires compared to last year.

The number of farm fires during the stubble burning period (September 15 to November 30) has varied in recent years. Punjab recorded 49,922 fires in 2022, 36,663 in 2023, and 10,909 in 2024. Haryana saw 3,661 cases in 2022, 2,303 in 2023, and 1,406 in 2024. Uttar Pradesh reported 3,017 fires in 2022, 3,996 in 2023, and 6,142 in 2024, while Rajasthan recorded 1,268 in 2022, 1,775 in 2023, and 2,772 in 2024. Delhi recorded 10 cases in 2022, five in 2023, and 13 in 2024.

Experts emphasize that wind speed and direction are crucial in determining how smoke from burning sites affects Delhi. The timely withdrawal of the monsoon and earlier festivals this year could provide an advantage, as festivals will occur in October before winter conditions fully set in. Calm winds and low temperatures during winter typically worsen pollution accumulation, making the timing of crop fires a critical factor in Delhi's air quality.

Anumita Roychowdhury, Executive Director of Research and Advocacy at the Centre for Science and Environment, stressed the need for early interventions to scale up the implementation of key strategies to prevent stubble burning and address the unique challenges of this year. These strategies include providing farmers with crop residue management machines and coordinating waste collection.

BS Vohra, an environmental activist, advocated for a coordinated, multi-state strategy to curb air pollution in Northern India, including preventing stubble burning through farmer support and alternatives, enforcing emission norms on vehicles and industries, controlling construction dust, and improving waste management. He also emphasized the need for better public transport, green infrastructure, and real-time air quality monitoring and suggested activating a "Winter Action Plan" with clear roles, emergency measures, and public awareness campaigns before winter.

Despite Delhi's relatively cleaner air in July 2025, with the lowest average Air Quality Index (AQI) for July since 2015, the city still faces significant air pollution challenges. An Air Quality Life Index (AQLI) 2025 report stated that residents in Delhi-NCR could lose 8.2 years of life expectancy due to air pollution.

While Delhi's air quality has shown improvement, with 118 days of good, satisfactory, or moderate air quality in 2025, authorities and residents must remain vigilant and proactive. The coming weeks will be critical in determining whether effective management of stubble burning can prevent the smog-filled winters of previous years.