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.

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.

Delhi residents woke up to ‘severe’ air quality on Thursday morning (November 14), a day after the national capital recorded the worst AQI in the country, with dense fog blanketing the NCR, reducing visibility.

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.

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.