The late withdrawal of monsoon from Delhi is likely to "influence air quality negatively" by the weekend, a government forecasting agency has said.
The city recorded an air quality index (AQI) of 116 on Sunday morning, which falls in the "moderate" category. On Saturday, the 24-hour average AQI was 165.
An AQI between 0 and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.
The Ministry of Earth Science's air quality monitor, SAFAR, said dust from arid regions in the southwest has started affecting Delhi.
"A marginal increase in farm fires was also being observed," it said.
The monsoon withdrawal from Delhi will commence on Monday, according to the India Meteorological Department. "This late withdrawal and associated stagnant winds are likely to influence air quality negatively by the weekend," it said.
Pawan Gupta, a senior scientist at Universities Space Research Association, NASA, said satellites detected around 280 fires in Punjab on Saturday.
He said the dust transport from the west is also expected to affect air quality in northern-central India till Monday.
