Delhi's air quality remained under 'very poor' category on Saturday, November 14. As per weather experts, emissions from firecrackers and calm winds might deteriorate pollution-levels later in the day, with the air likely to become 'severe' on Diwali night.
However, if no crackers are burnt on Diwali day then the PM2.5 concentration in Delhi might be the lowest in the last four years, the Ministry of Earth Sciences' air quality monitor, SAFAR, said.
Additionally, the Indian Meteorological Department (IMD) has predicted light rain on Sunday (the next day of Diwali) in the national capital under the influence of a western disturbance.
Kuldeep Srivastava, head of the IMD's regional forecasting centre, said light rain might improve air quality due to an increase in wind speed. On Sunday, the maximum wind speed is expected to be around 12 to 15 kilometers per hour.
On the other hand, V K Soni, head of the IMD's environment research centre, said calm winds and firecracker emissions may push air quality into the severe zone on Diwali night. The wind speed is expected to pick up thereafter and wind direction will be east-southeasterly, he stated. There will be a significant improvement in air quality by November 16, Soni added.
According to Delhi Pollution Control Committee (DPCC), the air quality index (AQI) at Anand Vihar stood at 424 (severe), in IGI airport 328 (very poor), in ITO 400 (very poor), and in RK Puram 354 (very poor) on Saturday morning.
The neighbouring cities of Faridabad (323), Ghaziabad (412), Noida (362), Greater Noida (350), and Gurgaon (338), which fall in the National Capital Region (NCR), also recorded their AQI in the "very poor" and severe categories.
Delhi recorded a 24-hour average AQI of 337 on Diwali last year (October 27), and 368 and 400 the next day. Thereafter, pollution levels remained in the severe category for three days on the trot.
In 2018, the 24-hour average AQI (281) on Diwali was recorded in the poor category. It deteriorated to 390 the next day and remained in a severe category on three consecutive days thereafter.
The IMD has said that a fresh western disturbance is likely to increase wind speed and improve air quality in Delhi-NCR post-Diwali.
Meanwhile, the National Green Tribunal (NGT) had on Monday imposed a total ban on the sale or use of all kinds of firecrackers in the National Capital Region (NCR) from November 9 midnight to November 30 midnight.
The Central Pollution Control Board (CPCB) has also ordered the closure of hot mix plants and stone crushers in Delhi-NCR till November 17. It also asked the governments of Punjab and Haryana to take immediate stringent action to curb stubble burning and ordered authorities in Delhi-NCR to strictly check biomass burning.