According to the System of Air Quality and Weather Forecasting and Research (SAFAR)-India, the overall air quality in the national capital is in the 'very poor' category with an Air Quality Index (AQI) of 327

After being in the 'poor' category with an AQI of 286 on Saturday, the city's AQI has been in the 'very poor' category since then with 309 on Sunday and 322 on Monday

Meanwhile, residents of the national capital criticised the Delhi government for the deteriorating air quality

In the Delhi University area and Pusa, the quality of air was recorded as 'very poor' and 'poor' with AQI at 316 and 201, respectively at 7 am today

The quality of air in the IIT Delhi region also remained in the very poor category with an AQI of 388

The quality of air at the Airport (T3) and Mathura Road was also in the very poor category, with an AQI of 329 and 330 respectively

Meanwhile, Noida recorded an AQI of 375 (poor) and Gurugram 249 (poor)

Air Quality Index (AQI) is a tool for effective communication of air quality status to people in terms, which are easy to understand. It transforms complex air quality data of various pollutants into a single number (index value), nomenclature, and colour. The AQI from 0 to 100 is considered good, while from 100 to 200 it is moderate, from 200 to 300 it is poor, and from 300 to 400 it is said to be very poor and from 400 to 500 or above it is considered as severe