AQI 'moderate', likely to turn 'poor' by Friday

New Delhi: The national Capital's air quality was recorded in the 'moderate' category on Tuesday, while a government forecasting agency said it is likely to turn 'poor' by Friday.

Delhi recorded a 24-hour average air quality index (AQI) of 177, which falls in the 'moderate' category. It was 159 on Monday.

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'.

"Favourable ventilation condition is likely to keep Delhi's AQI in the 'moderate' category for the next two days," the System of Air Quality and Weather Forecasting and Research (SAFAR) said.

However, it said, the late withdrawal of monsoon and associated stagnant winds are likely to influence Delhi's air quality negatively by the weekend. By October 2, the air quality is likely to slip to the "lower end of the poor category", SAFAR said.

The monsoon started receding from Rajasthan on Monday. It is expected to withdraw from the rest of northwest India in the next three days, according to an India Meteorological Department official.

SAFAR observed an "increase" in farm fires on Monday around Punjab, Haryana, and neighbouring border regions, but said no significant impact is expected on Delhi's AQI in the next two days.