With passing days, Delhi's air quality is deteriorating further and now it stands closer to the 'severe plus' category.

The severe category is a stage which might trigger the implementation of the odd-even car rationing measure in the capital.

The city's air quality index stood at 437 at 7 am, worsening from 419 at 4 pm on Thursday. The capital's 24-hour average AQI, recorded at 4 pm every day, was 401 on Wednesday, 397 on Tuesday, 358 on Monday, 218 on Sunday, 220 on Saturday, and 279 on Friday.

The relatively better air quality last weekend is attributed to rain. Air pollution levels surged in the following days due to intense firecracker bursting on Diwali night and a resurgence in stubble burning in the neighbouring states.

These effects were compounded by unfavourable meteorological conditions, primarily calm winds and low temperatures, hindering the dispersion of pollutants. Neighbouring Ghaziabad (374), Gurugram (404), Greater Noida (313), Noida (366), and Faridabad (415) also recorded very poor to severe air quality.