The national capital woke up to a deteriorating pollution situation Sunday with the air quality falling into the “very poor” category again, a day after showing slight improvement.

Delhi’s air quality index (AQI) stood at 364 as of 7 am, worsening from 290 recorded under the ‘poor’ category early Saturday.

Out of the 26 air pollution monitoring stations in the city, air pollution levels reached the “severe” category (AQI above 400) at Nehru Nagar with AQI 431,followed by Anand Vihar with AQI 427.

The India Meteorological Department (IMD) forecast that the air quality is likely to be in ‘very poor’ category until Tuesday (Nov 5). Additionally, the outlook for subsequent six days is that the air quality is likely to be in the ‘very poor’ category.

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”, 401 and 450 “severe” and above 450 “severe plus”.

On Diwali, the city’s 24-hour AQI, recorded at 4 PM, stood at 339, while on the day after the festival, it was 362, according to the Central Pollution Control Board (CPCB).

Meanwhile, the adjoining area of Ghaziabad also recorded its 24-hour average AQI in the “very poor” category with an AQI of 330. However, Gurugram, Greater Noida and Noida recorded slightly better AQI levels at 209, 250 and 269, respectively, falling in the “poor” category.

Lucknow observed the air quality worsening with an AQI of 327 falling under the ‘very poor’ category and is expected to remain the same until Tuesday, according to IMD.

The overall air quality in Pune was observed under the ‘poor’ category with an AQI of 236 this morning. However, the forecast shows a slight decrease in AQI is likely later in the day improving the air quality to ‘moderate’ category till Tuesday.

Mumbai maintained its air quality in the ‘moderate category’ with an AQI of 141. It is likely to increase later in the day pushing the quality to the ‘poor’ category.

The overall air quality of Bengaluru was observed under ‘satisfactory’ category on Sunday morning and is expected to remain the same with the AQI at 75.