The air quality index continued to fluctuate between the "severe" and "very poor" categories in Delhi. The air quality in the Delhi-NCR remained grim in the high concerning zone as several areas continued to be in the ‘severe’ AQI category on Sunday. Despite the clear sky and bright sun, a layer of smog was visible all over Delhi-NCR.  According to the Central Pollution Control Board (CPCB), the average air quality index (AQI) in the national capital is 318, which is in the ‘very poor’ category.  CPCB data identified PM2.5 as the primary pollutant, with its levels recorded at 138 at 3 pm. According to IQ Air, PM2.5 concentration is currently 22.2 times the World Health Organization annual PM2.5 guideline value.

The Decision Support System for Air Quality Management in Delhi pointed out the transport sector is the most significant contributor at 18.155 percent.

Notably, there is a ban on entry of non essential trucks from other states to Delhi and around four lakh vehicles are off the road due to stage IV of the Graded Response Action Plan imposed in the Delhi-NCR. While the residential sector contribution is 4. 557 percent, industries contributed 3. 667 percent, construction 2. 595 percent, energy sector 1. 564 percent, waste burning 1.651 percent, and road dust 1.361 percent

In the morning, the AQI in eight areas, remained above 400 and between 500. It was 410 in Alipur, 412 in Anand Vihar, 408 in Nehru Nagar, 404 in Vivek Vihar, and 409 in Wazirpur.Whereas in other parts of the national capital, the AQI level remained between 300 and above 400. It was 392 in Ashok Vihar, 313 in Aya Nagar, 362 in Burari Crossing, 353 in Chandni Chowk, 354 in Mathura Road, 356 in Dr Karni Singh Shooting Range, 400 in Dwarka Sector 8, 327 in IGI Airport, 380 in Dilshad Garden, 340 in Jawaharlal Nehru Stadium, 302 in Lodhi Road, 372 in Major Dhyanchand Stadium, 328 in Mandir Marg, 319 in Najafgarh, 348 in North Campus DU, 371 in Okhla Phase-2, 388 in Patparganj, 370 in Punjabi Bagh, 327 in Pusha, 373 in RK Puram, 382 in Rohini, 382 in Shadipur 385, 357 in Siri Fort and 340 in Sri Aurobindo Marg.

Shallow fog reported at Safdarjung airport during early morning today. Safdarjung airport recorded lowest visibility 800 m during at 0530 hours which improved thereafter becoming 1200m at 0730 hours IST. Mainly clear sky condition with wind speed less than 10 kmph west direction prevailed over the region in the forenoon today.

The air quality improved as the winds picked up, in the morning hours on Sunday. The average wind speed remained around 3 kmph, but this increased to 6 to 10 kmph by noon, according to data from the Delhi Pollution Control Committee. A favourable wind speed of more than 10 kmph was reported in a few stations. At Alipur, for instance, the wind speed reached above 10kmph as of 10 am, Sunday.

 Predicted maximum mixing depth is likely to be 1800 m on Saturday. The ventilation index lower than 6000 m2/s with average wind speed less than 10 kmph is unfavourable for dispersion of pollutants.

Delhi's air quality has remained hazardous for nearly a month. On October 30, it first slipped into the 'very poor' category and stayed there for 15 days. It worsened further last Sunday as Delhi recorded 'severe' air quality and stayed so on Monday and Tuesday.

By Wednesday, the air quality was in the 'severe plus' category. Favorable wind conditions brought slight relief on Thursday but the air quality began deteriorating again, nearing the 'severe' category, on Friday. Delhi's air quality slipped back to the 'severe' category on Saturday.  The situation was no better in other NCR cities. The AQI in Faridabad was 309, Gurugram 240, Ghaziabad 312, Greater Noida 304 and in Noida it was 309.

The maximum temperature was recorded 29 degree celsius while the minimum 12 degree celsius. Delhi, Punjab, Uttar Pradesh and Haryana are likely to record a further dip in temperatures over the next two to three days, IMD scientist Naresh Kumar said. The minimum temperature in the national capital was recorded at 12 degrees Celsius on Sunday. The weather department has forecast shallow fog during the morning or night hours, with the maximum temperature expected to hover around 28 degrees Celsius.