Delhi woke up to a layer of haze on Wednesday, October 21, as air quality deteriorated following the Dussehra festivities. With cooler weather setting in and winter approaching, the national capital is expected to see its Air Quality Index (AQI) remain in the poor category until October 23, according to the Air Quality Early Warning System (AQEWS).

The changing weather and declining air quality signal the start of another challenging period for Delhi, where pollution levels tend to rise during the winter months.

Delhi recorded an AQI of 179 on Tuesday, placing it in the moderate category. However, the forecast points to a deterioration over the coming days. The last time the capital recorded poor air quality was on July 13, when its AQI reached 246.

Under the Central Pollution Control Board's classification, an AQI between 201 and 300 falls in the poor category, while readings between 301 and 400 are classified as very poor. An AQI of 401 to 500 is considered severe.

Temperatures have also remained below seasonal averages at several weather stations across the city. At Safdarjung, Delhi's primary meteorological station, the maximum temperature was 31.8 degrees Celsius and the minimum was 17.7 degrees Celsius.

Palam recorded a maximum of 29.3 degrees Celsius and a minimum of 17.3 degrees Celsius. At Lodhi Road, the maximum temperature stood at 31.4 degrees Celsius, while the minimum was 17 degrees Celsius.

The India Meteorological Department has forecast no rainfall over the coming week. Delhi is likely to have mainly clear skies on October 21, 22 and 23, followed by partly cloudy conditions on October 24 and 25. Without rain, the natural removal of airborne pollutants may be limited, although wind speed and other atmospheric conditions will also influence pollution levels.

Stubble burning and winter measures add to pollution concerns

Crop residue burning in neighbouring states remains one of the seasonal factors affecting Delhi's air quality. The ICAR-Indian Agricultural Research Institute recorded 19 incidents of stubble burning across six monitored states earlier this month. Punjab and Uttar Pradesh reported seven incidents each, followed by four in Madhya Pradesh and one in Haryana.

Smoke from agricultural fires can travel towards the national capital, with the impact depending on prevailing weather conditions and the atmosphere's ability to disperse pollutants.

The Delhi government has announced a series of measures under its winter pollution action plan, which is scheduled to run from November 1 to February 28 under Chief Minister Rekha Gupta's plan.

The measures include a 'No Pollution Under Control Certificate (PUCC), No Fuel' policy, under which vehicles without valid pollution certificates will not be supplied fuel at petrol pumps. Automatic Number Plate Recognition cameras are also planned to strengthen enforcement.

Vehicles registered outside Delhi that do not meet BS-VI emission standards will face entry restrictions from November 1, 2026, to January 31, 2027. CNG and electric vehicles will be exempt from these restrictions.

The plan also provides for restrictions on dust-generating demolition and outdoor civil construction activities from November 1, 2026, to January 31, 2027, along with a complete ban on construction and demolition work from December 10 to January 20. A proposed 50 per cent work-from-home arrangement for offices is another part of the plan.

As Delhi moves further into the cooler months, the combination of changing weather, emissions and agricultural fires is expected to remain a key concern for the city's air quality.

With IANS inputs