Delhi’s AQI tops 300 as capital braces for worsening smog

• Delhi’s AQI reached 307 on Monday morning, entering the “very poor” category for the first time this season.

• Jahangirpuri recorded “severe” air quality at 417, while 36 monitoring stations reported “very poor” readings.

• Unfavourable weather could worsen pollution across Delhi-NCR over the next seven to 10 days, a meteorologist warned.

Delhi’s air quality slipped into the “very poor” category for the first time this season on Monday, as thick haze covered the capital and pollution surged following a brief spell of cleaner air after last week’s rain.

The air quality index stood at 307 at 7.05 am. The deterioration followed a rapid rise over the weekend, with the city’s 24-hour average AQI climbing from 117, in the “moderate” category, on Saturday to 261, classified as “poor”, on Sunday, according to the Central Pollution Control Board’s 4 pm bulletin.

On Friday, rain had brought the AQI down to 60, giving Delhi its cleanest October day in four years. That improvement proved short-lived.

Readings were available from 58 of the capital’s 59 monitoring stations on Monday morning. Of these, 36 registered “very poor” air quality. Jahangirpuri was the only location in the “severe” category, recording an AQI of 417. Five stations reported “moderate” conditions, while the remaining 16 were in the “poor” range.

Under the CPCB’s classification, AQI readings between 301 and 400 are considered “very poor”, while those between 401 and 500 fall in the “severe” category.

Fine particulate matter, or PM2.5, was the dominant pollutant at 51 of the 58 reporting stations at 6 am on Monday. PM10 was the main pollutant at the other seven. At the same time on Sunday, PM2.5 had dominated at 46 of 57 stations, with PM10 leading at 11.

Delhi last recorded a “very poor” daily average AQI on 11 February, when the reading was 305. Earlier that month, it had reached 339 on 4 February.

The latest deterioration comes a week before Diwali, when firecracker emissions typically increase the pollution burden.

Meanwhile, NASA satellite observations detected 1,394 farm fires across Punjab and Haryana between 1 October and 1 November. Punjab accounted for 1,249 detections and Haryana for 145, with 171 fires recorded across the two states on 1 November alone.

The total was below the 1,861 fires detected during the corresponding period last year. However, the figures require caution because a growing share of stubble burning takes place later in the day, potentially escaping detection during the satellite’s pass at around 1.30 pm.

Meteosat observations showed that approximately 98 per cent of recorded fire heat in 2025 occurred after 3 pm, compared with 94 per cent in 2024, highlighting the limitations of afternoon satellite counts.

Meteorologist Navdeep Dahiya warned that conditions were becoming favourable for a sustained build-up of smog across Delhi-NCR and the northern plains.

In a post on X, he said north-westerly winds and calm conditions would allow emissions to remain suspended in the atmosphere for longer. He added that many sensors across the region were reporting AQI readings above 300, with some moving towards the 400–500 range.

Dahiya said no favourable change in weather was expected over the next seven to 10 days, raising the prospect of worsening smog in the days ahead.

With agency inputs