Delhi winter pollution could be worse this year: 47 farm fires already recorded, Super El Nino, late Diwali and delayed harvesting likely to complicate things

Are you witnessing morning haze and wondering if winter pollution is already here, you are not wrong. The annual stubble-burning season has started in north India. As many as 47 farm-fire incidents were recorded across Punjab, Haryana, Uttar Pradesh, Rajasthan and Madhya Pradesh between September 15 and 23, according to satellite data compiled by the Indian Agricultural Research Institute. Punjab accounted for 25 of these cases and Uttar Pradesh 19, while Haryana, Rajasthan and Madhya Pradesh reported one each, a TOI report stated.

The numbers are still small compared with what is normally seen later in the season. Farm fires typically increase through October and reach their highest levels in the first 10 days of November. The stubble-burning window generally runs from September 15 to November 30. This year, however, weather conditions could make the pollution story more complicated.

Why Super El Nino may make matters worse for Delhi pollution

One factor being watched closely is the expected impact of a strong El Nino event on winter weather. Gufran Beig, founder of the System of Air Quality and Weather Forecasting and Research (SAFAR) and chair professor at the National Institute of Advanced Studies, said fewer western disturbances could mean fewer episodes of winter rain over Delhi.


Western disturbances can bring rain and help temporarily clear pollutants from the atmosphere. If such weather systems are less frequent, pollution from different sources can remain suspended for longer. Beig also expects relatively mild winter conditions. That does not automatically mean cleaner air.

His assessment is that slower winds could become important because weak ventilation can allow pollutants to accumulate near the region rather than being dispersed. There is another factor in play: Punjab has recorded a significant rainfall deficit this monsoon, while sowing has been delayed. That could push harvesting towards late October and potentially extend the period during which farmers burn crop residue.

Diwali and peak farm fires will come close together

The timing could add another complication. Diwali falls on November 8 this year, around the period when farm-fire activity is expected to be at or near its seasonal peak. That means several pollution sources could overlap as temperatures begin to fall and winds become weaker.

The important point, however, is that stubble burning is only one contributor to Delhi-NCR's winter pollution. Its effect depends heavily on wind direction, atmospheric conditions and the intensity of fires in neighbouring states.

Delhi Winter Pollution: What happened last year?

The contribution of farm fires to Delhi's PM2.5 was relatively limited for much of 2025. According to Decision Support System data cited in the report, the share of stubble burning in Delhi's PM2.5 crossed 10% on only eight days last year and exceeded 20% on just one day. On most days, it remained below 5%.

The comparison with 2024 is notable. The farm-fire contribution crossed 20% on 14 days that year. That does not mean farm fires stopped being a concern. It shows how much their impact can vary from one season to another depending on the combination of fire activity and weather conditions.

Farm fires have fallen in some states, but not everywhere

There has been a broad decline in crop-residue burning in some major northern states. Punjab recorded 5,114 farm fires in 2025, compared with 10,909 in 2024. Haryana's tally fell from 1,406 to 662 during the same period.

But Uttar Pradesh moved in the opposite direction, with paddy-residue burning incidents increasing from 6,142 in 2024 to 7,290 in 2025. Rajasthan also recorded a small rise, from 2,772 to 2,890. Delhi's own reported cases declined from 13 in 2024 to five in 2025.

Early 2026 numbers should also be interpreted carefully. Satellite monitoring has limitations because a fire can go undetected if it occurs outside the period when a satellite passes overhead.

Why the next few weeks matter

Environmental experts say simply counting farm fires will not be enough. Anumita Roychowdhury, executive director of research and advocacy at the Centre for Science and Environment, said the trajectory this season will depend on enforcement as well as how effectively crop residue is managed on the ground.

That includes both in-situ management, where residue is treated within the field, and ex-situ use, where crop waste is collected and diverted for industrial or other uses. The government is also continuing satellite-based monitoring of crop-residue burning across Punjab, Haryana, Uttar Pradesh, Rajasthan and Delhi. The monitoring system uses satellite fire detection and sends alerts to field-level officials for action.

So the 47 fires recorded so far are not, by themselves, a forecast of Delhi's winter air quality. The bigger question will be what happens when harvesting accelerates in October, farm fires rise in November and weather conditions become less favourable for dispersing pollutants. This is the period authorities will be watching most closely.