The AQI in Vasant Vihar's C Block area was 1,336 at 11.55 am, as per Swiss air quality monitor IQAir. An AQI above 300 is considered 'hazardous' for humans.

Air quality reaches the ‘severe’ category with an AQI of 426 at 9 a.m. on Thursday, impacting health and ranking as second most polluted city.

Delhi recorded the worst air quality in India on Wednesday with a severe AQI of 418 while Noida and Gurugram also faced very poor levels.

Every year, Delhi and northern states battle hazardous air during the winter months of October to January due to plummeting temperatures, smoke, dust, low wind speed, vehicular emissions and crop stubble burning. This time, experts say that the condition is likely to get worse in the coming days.

On Thursday morning, Delhi's air quality hit severe levels, with AQI readings reaching as high as 473 in some areas. Despite the hazardous level, the CAQM opted to monitor conditions further before implementing Stage 3 of the Graded Response Action Plan (GRAP).

Residents of Delhi, Noida, Ghaziabad, Gurugram, and nearby areas awoke to a thick layer of smog on Wednesday, which brought visibility down to near-zero levels. The air quality index (AQI) in Delhi stayed in the ‘very poor’ range,