Delhi recorded an air quality index of 95 at 6am on Saturday after rain cleared the air. While the city got its cleanest October day on Friday with an AQI of 60, pollution levels rose slightly. Shallow fog covered the capital as visibility stayed steady at 500 metres in Safdarjung.
Delhi recorded an air quality index (AQI) of 95 at 6am on Saturday, compared with 60 in the Central Pollution Control Board's (CPCB) 4pm bulletin on Friday. The air quality remained in the satisfactory category, although the increase indicated a deterioration from the previous day's unusually clean conditions.
At 6am , CPCB data showed PM2.5 as the predominant pollutant at 17 of Delhi's 58 reporting stations and PM10 at four stations. At the same time on Friday, PM2.5 was the main pollutant at 42 of 53 reporting stations, while PM10 was recorded as the main pollutant at 10 stations.
The visibility at Safdarjung remained steady at 500 metres from 2.30am, while at Palam it remained unchanged at 800 metres from 5am. Both stations reported shallow fog.
According to IMD classification, visibility between 999 metres and 500 metres is categorised as shallow fog. Visibility between 499 metres and 200 metres is classified as moderate fog, while 199 metres to 50 metres is dense fog. Visibility below 50 metres is categorised as very dense fog.
The fog comes a day after an unusual interaction between Cyclone Arnab and a western disturbance triggered heavy rain and thunderstorms across the Capital, washing pollutants out of the atmosphere.
Delhi recorded an AQI of 60 in Friday's 4pm bulletin, its cleanest October day in four years. The average AQI for the first 30 days of October stood at 167, putting the city on course to record its cleanest October since CPCB began publishing daily AQI bulletins in 2015.
The station recorded 61.4mm of rainfall in the 24 hours ending 8.30am on Friday, the sixth-highest 24-hour rainfall for October since 1951.