Delhi's air quality slipped into the severe category today due to unfavorable meteorological conditions slowing down dispersion of pollutants, authorities said.
The Central Pollution Control Board (CPCB) data showed the overall air quality index (AQI) of Delhi at 412, which falls in the severe category, while the System of Air Quality and Weather Forecasting (SAFAR) recorded an AQI of 388, i.e. very poor category.
Consistent day-night trend of pollution level observed in Delhi
The SAFAR also pointed out towards consistent day-night trend.
"During night, combination of calm wind and colder conditions is elevating the pollution level, wherein many locations, 24-hour rolling average (AQI) is touching severe levels for a few hours, whereas during the day, wind speed is picking up slightly and temperature is increasing to keep the level in the very poor range," it said.
Delhi's air quality swinging between 'very poor' and 'severe' category
The air quality slipped into the severe category this morning for the fourth time in 10 days.
Delhi's air quality has oscillated between the very poor and the severe categories during this period.
According to the CPCB data, 27 areas recorded severe pollution, while eight areas witnessed very poor air quality.
In the NCR, Ghaziabad, Gurgaon, and Noida recorded severe air quality.
City recorded second-highest pollution level of year on December 23
The overall PM2.5 level was recorded at 339 and the PM10 level at 506 in Delhi, the CPCB said.
The national capital recorded its second-highest pollution level of the year on 23 December with an AQI of 450.
The air quality remained severe on 25-26 December.
The air quality had moved to the very poor category on 27 December.
Forecast: Air quality may deteriorate tomorrow
The air quality Thursday had again worsened and turned severe.
According to the SAFAR, the air quality over Delhi has deteriorated slightly and touched the upper side of the very poor category.
"Air quality over Delhi may improve slightly as winds are relatively high during the day but predicted to deteriorate by tomorrow as wind speed is unlikely to remain the same," it said.
Air quality will fluctuate between 360-380 for next three days
Cold wave conditions are likely to persist at least for the next two days, the SAFAR said. "The air quality index will continue to fluctuate between 360-380 for the next three days, which comes under the 'very poor' category," it added.