NEW DELHI: Delhi's air quality was recorded in the 'poor' category on Saturday (November 21) and is likely to deteriorate further amid a dip in the minimum temperature. A change in the wind direction has also increased the share of stubble burning in the city's pollution slightly.
The overall Air Quality Index (AQI) was 263 at 9 am. The 24-hour average AQI was 296 on Friday. It was 283 on Thursday and 211 on Wednesday.
According to Central Pollution Control Board data, the AQI was at 265 in Anand Vihar, 296 in Ashok Vihar, 271 in Old Delhi's popular marketplace Chandni Chowk, 303 in Dwarka Sector 8 and 290 in RK Puram, all falling under the 'poor' category.
According to government agencies, the city's air quality recorded a marginal improvement on Saturday morning due to favourable wind speed. The central government's Air Quality Early Warning System for Delhi said the air quality in Delhi-NCR was likely to improve further to the 'moderate' category on Saturday.
The central agency said the AQI is likely to deteriorate to the upper end of the 'very poor' category between Tuesday and Friday as "unfavourable meteorological conditions" are predicted during that period.
Around 800 farm fire counts were observed over Punjab, adjoining Pakistan and Haryana on Friday, it said.
According to the Ministry of Earth Sciences' air quality monitor, SAFAR, stubble burning accounted for 15 per cent of Delhi's PM2.5 pollution on Friday. The figure was 20 per cent on Thursday, 8 per cent on Wednesday and 3 per cent on Tuesday.
Temperatures were appreciably below normal at many places in Punjab, Haryana and Delhi on Nov 20, with the national capital recording a minimum of 7.5 degrees Celsius, the lowest in the month of November in 14 years. It is Delhi's lowest minimum temperature in November since November 29, 2006, when the city recorded a minimum of 7.3 degrees Celsius, said Kuldeep Srivastava, the head of the IMD's regional forecasting centre.
"The criteria has been met on Friday. We will declare a cold wave in Delhi if the situation persists on Saturday," Srivastava said.