Delhi’s air quality slipped to the ‘very poor’ category on Tuesday morning, after witnessing a marginal improvement in previous days. This marks the Delhi Air Quality Index (AQI), making a return to the prolonged pollution spell the city has been battling this winter.

Following 24 days of ‘very poor’ air, often edging towards the ‘severe’ zone, Delhi’s AQI improved to ‘poor’ on Sunday with a reading of 279.

By 9 AM on Tuesday, Delhi’s AQI was at 340, according to Central Pollution Control Board (CPCB) data. Today morning, the area around the famous Akshardham Temple was shrouded in a layer of toxic smog, with an AQI of 383, classified as ‘very poor’.

In some areas, the AQI was closer to the dark red zone, the ‘severe’ category. The CPCB recorded an AQI of 383 in the Ghazipur area on Tuesday morning as a layer of toxic smog blanketed the city.

The areas around India Gate, Kartavya Path, and ITO also recorded air quality levels closer to severe.

The CPCB classifies an AQI between 201 and 300 as ‘poor’, 301 and 400 as ‘very poor’, and 401 and 500 as ‘severe’.

Before Sunday, Delhi’s last recorded AQI in the ‘poor’ category this season was on 5 November, when the reading stood at 202.

Monday’s AQI followed a week-long trend – 279 on Sunday, 305 on Saturday, 369 on Friday, 377 on Thursday, 327 on Wednesday, 352 on Tuesday and 382 on Monday.

According to the Sameer app developed by the CPCB, no monitoring station in Delhi recorded ‘severe’ air quality on Monday, a trend similar to that observed over the weekend, in contrast to eight stations falling into the ‘severe’ zone on Friday.

November’s average AQI stood at 357 – in the ‘very poor’ range but slightly better than 374 in 2024 and 366 in 2023. The city saw no ‘good’, ‘satisfactory’, or ‘moderate’ air quality days last month. Instead, it recorded three ‘poor’, 24 ‘very poor’, and three ‘severe’ days.