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The fires were reported in Punjab, Haryana and Uttar Pradesh. Between September 15 and October 15, satellites detected 327 farm fires, according to the Indian Agricultural Research Institute (IARI). On the same dates last year, the count was 475.

Delhi's air quality showed little change. Its average Air Quality Index (AQI) over the 31-day period was 133, according to the Central Pollution Control Board (CPCB). Last year it was 135.

Punjab recorded 185 farm fires this season, according to IARI data, slightly more than the 178 reported during the same period last year.

Uttar Pradesh had 134, roughly half the 271 reported last year. Haryana recorded eight, down from 26.

Most days were quiet. On 20 of the 31 days, satellites spotted fewer than 10 fires, IARI data show. The worst day was Oct 13, with 55 fires, 51 of them in Punjab. DELHI'S AIR QUALITYDelhi has not had a single day worse than Moderate this season, CPCB data show. The Moderate category covers AQI readings of 101 to 200.

The worst day was Oct 4, when the AQI reached 187. On Oct 15, it was 149.

Some years had more farm fires and cleaner air. In 2021, satellites spotted 3,256 fires on these same dates, and Delhi's index averaged 112, IARI and CPCB data show. In 2022, there were 1,497 fires, and the average was 111.WHAT THE NUMBERS CANNOT TELL US

These numbers put farm fires and air side by side. They do not tell us how much of Delhi's dirty air comes from the fires. And a fire spotted by a satellite is not the same as a field burned.THE WORST MAY STILL BE AHEAD

The first month of the harvest season is usually the quieter period. From 2019 to 2025, at least 87 per cent of the fires came after October 15, IARI data show.Fires have fallen a lot over the years. Satellites spotted 82,021 fires from September 15 to November 30 in 2021, IARI data show. In 2025, they spotted 13,069, which is 84 per cent fewer.

But the number of days with severely polluted air in Delhi did not fall in step with the fires. The city recorded 28 days in the Very Poor or Severe categories in 2021, according to CPCB data. In 2025 it had 34.

The Very Poor category means an index of 301 or more. From 2019 to 2025, Delhi had 25 to 38 such days each season, CPCB data show. Almost all of them came after mid-October.

Last year, the fire count stood at 475 by October 15. By November 30, it was 13,069.DATA NOTE

FARM Fires: IARI's daily reports of farm fires spotted by satellite in Punjab, Haryana and Uttar Pradesh, Sept 15 to Nov 30 each year since 2019 (the 2019 and 2020 reports start Oct 1).

Air: CPCB's daily index for Delhi, an average of the 24 hours up to about 4 -5 p.m.

All comparisons are by India Today's Data Intelligence Unit.- Ends

Dipu Rai is an investigative and data journalist based in New Delhi focusing on data-driven stories on finance, health, politics and environment. He is also actively involved in analyses and visualisations of data at India Today's Data Intelligence Unit (DIU).

Dipu is well-versed in SQL, Python, R, Tableau and produces prototype visualisations quickly as per requirement. He is specialised in dealing with a variety of datasets with parsing, scraping and cleaning. Doing Spatial analysis is his hobby, and he frequently uses location intelligence platforms like Carto and QGIS.

After completing the master in economics, Dipu has started his career as a business journalist. He has more than ten years of experience in broadcast, print and digital platforms.

Dipu's work has sparked several financial investigations and won some of journalism's highest honours. He was awarded the Redink Award, in 2015 for financial crime reporting. He has translated Raymond Williams's book 'Television' in Hindi. His hobbies include reading codes, learning new visualisation techniques. In his spare time he likes to read books, listen to music and watch films.