For the fifth consecutive day, the air quality in Delhi remained "poor", with the average air quality index (AQI) recorded at 256 on Friday morning, as per System of Air Quality and Weather Forecasting and Research (SAFAR). Several parts of the national capital saw the AQI dipping to "very poor" category, mostly due to a drop in temperature and wind speed.


Monitoring agencies said that the air quality is likely to deteriorate over the weekend due to unfavourable meteorological conditions, PTI reported. 


On Thursday, Delhi's average AQI was 256. It was recorded at 243 on Wednesday and 220 on Tuesday. On Saturday, the air quality is likely to be 'very poor'.


The worst air quality was recorded around Delhi University area at 307, which falls in the  "very poor" category. As per SAFAR, the AQI at Noida was 208 (poor) and Gurugram 252 (poor).


As per the air quality yardstick followed by SAFAR, an AQI between zero 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".


Delhi Environment Minister Gopal Rai said the 15-point action plan to mitigate air pollution launched last month was being implemented on the ground.


"The data says that in AQI, the level of PM10 is decreasing and that of PM2.5 is increasing. For this, the 'Red Light on, Gaadi off' campaign has been started since yesterday...Through this campaign, we are trying to control the unnecessary burning of fuel and the spreading of pollution," ANI quoted Gopal Rai as saying.


Amid worsening air quality in the national capital, the Delhi government deployed anti-smog gun in the Anand Vihar area on Thursday to sprinkle water.


While stubble burning continues unabated in parts of Punjab and Haryana, the number of farm fires have been comparatively less this time compared to last year, experts have said after analysing satellite data, a TOI report said.


To mitigate pollution, the second phase of the Graded Response Action Plan (GRAP) has come into effect in Delhi. Under GRAP-2, which are a set of guidelines to control pollution around Delhi-NCR, there will be a ban on the use of coal and wood-fired stoves, increase in frequency of CNG and electric buses, usage of anti-smog guns, etc.