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.

A study published in June found that air pollution killed 135 million people over the last four decades around the world, with India and China accounting for the bulk of the fatalities. In 2023, Delhi’s AQI was recorded between 445 and 520 just a day after Diwali, placing it firmly in the “severe” category.

A toxic haze enveloped India's national capital on Wednesday morning as temperatures dropped and pollution surged, reducing visibility in some parts and prompting a warning from airport authorities that flights may be affected.

Delhi overtook Pakistan ’s Lahore as the world’s most polluted city in Swiss group IQAir’s live rankings, with an air quality index (AQI) score of more than 1,000, which is considered “hazardous”, but India ’s pollution authority said the AQI was around 350.

The air quality index (AQI) had surged to 366 according to real-time data from the Central Pollution Control Board (CPCB) at 9 am.

Air pollution in India's national capital increased to 'severe' on an official index on Wednesday for the first time this season as temperatures and wind speeds dropped, reducing visibility and affecting some flights.

Almost a week after Diwali, Delhi still continues to battle with air pollution because it is still in the ‘very poor’ category as of November 9 with an AQI of 360. Mumbai, on the other hand, is now in the ‘moderate’ range,