Pollution in New Delhi on Monday morning fell to "very poor" after being "poor" as the air quality index (AQI) slipped to 346 at 7:00 am, according to System of Air Quality and Weather Forecasting And Research (SAFAR).
The AQI in adjoining areas of Noida, Gurgaon was registered at 315 and 355 respectively.
An AQI between 201 and 300 is 'poor', 301-400 'very poor' and 401-500 'severe'.
An AQI between 0-50 is considered good, 51-100 satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor, and 401-500 severe. Above 500 is severe-plus emergency category.
Air quality in the city improved from "very poor" to "poor" on Saturday and Sunday because of wind speed.
It was a cold breezy Monday morning with the minimum temperature settling at 16 degrees Celsius.
Humidity was recorded at 66 per cent.
On Sunday, the maximum and minimum temperatures were recorded at 28 degrees Celsius and 16 degrees Celsius respectively.
Meanwhile, acting on a slew of directions from the Supreme Court, implementing agencies have taken "major action" at 13 pollution hot spots in the national capital, including closing 23 polluting industrial units, over the last three days, officials said on Sunday.
Municipal corporations have lifted 400 metric tonnes of construction and demolition waste and 1,200 metric tonne garbage during the period, they said.
After the apex court directed a three-member Monitoring Committee to oversee the implementation of pollution-control measures, its chairman Bhure Lal visited the hotspots of Wazirpur, Ashok Vihar, Punjabi Bagh, Dwarka and R.K.Puram on November 8 and Narela, Bawana, Jahangirpuri, and Mundka on November 9, according to the officials.