New Delhi, Nov 14 (IANS): The national capital and the regions around it saw a slight improvement in air quality on Wednesday morning from "severe" to "very poor" due to overnight rain which may continue on Wednesday.

The Air Quality Index (AQI) of Delhi improved to 336 or "very poor" at 12 noon on Wednesday against 409 or "severe" at 4 p.m. on Tuesday.

The particle pollutants also dropped as major pollutant PM2.5 or particles with diameter less than 2.5 mm settled due to the rain.

"Rain helped with settling the suspended particles in air. This may continue as some regions in Delhi already saw light rain since morning," an India Meteorological Department (IMD) official told IANS.

Delhi received an average 7 mm rainfall till 8.30 a.m. on Wednesday.

"Aya Nagar has already recorded 1.1 mm rainfall after 8.30 a.m. There are chances that other regions of Delhi may also receive some rain," the IMD official said.

The larger suspended particles PM10 or particles with diameter less than 10 mm, dropped from the "severe" to the "moderate" category on Wednesday morning, according to the System of Air Quality and Weather Forecasting And Research (SAFAR).

The average PM2.5 at 12 noon on Wednesday across Delhi was 182 microgrammes per cubic meters against 271 units at 6 p.m. on Tuesday.

"Weather has improved in Delhi, but since the system has moved, the region may see a slight increase in pollutants tomorrow on Thursday due to calm winds. But after that north-westerly winds will improve the air quality," Mahesh Palawat, Director of private weather forecast group Skymet said.