The air quality of the national capital and the regions around it, which on Wednesday improved to 'very poor' from 'severe' due to overnight rains, may again drop, warn monitoring agencies. Delhi saw about 7 mm of rainfall till 8.30 a.m. on Wednesday, improving air quality by settling the particle pollutants. However, rains have also increased the moisture in the air, which according to the System of Air Quality and Weather Forecasting And Research (SAFAR), will trap the pollutants and worsen the air quality.

"After the isolated shower in part of Delhi, a lot of moisture is introduced in the air, making it heavy and increased the holding capacity which will force AQI to go to the 'severe' category from evening until late night as the ventilation is also reduced," SAFAR forecast said.