Whatever the causes of the smog, by one ranking Delhi was not just the most polluted city in the world, but “nearly five times as bad as the second most polluted city, Dhaka,” in Bangladesh next door, as Shashi Tharoor, a leader of the opposition in Parliament and best-selling author, posted on X.

Hundreds of millions of Indians breathe some of the world’s most toxic air all year round. Air pollution in the capital area that’s home to about 30 million people is especially stubborn. In winter, the cold weather actually makes the smog even worse — and potent.

Unhealthy

The AQI in Delhi remained in the severe category from Monday to Wednesday last week and thereafter witnessed slight improvement on Thursday and Friday. However, it deteriorated to the severe category on Saturday.

Delhi woke up to smog and 'very poor' air quality on Monday morning, with AQI in several areas exceeding 300. While GRAP IV restrictions remain in effect, authorities are set to review them, considering stubble burning and local transport as major pollution contributors over the weekend.

Delhi experienced a slight improvement in air quality as it dipped to the 'poor' category with an AQI of 278 on Monday. However, several areas still reported 'very poor' air quality. Authorities have implemented Stage-IV of the Graded Response Action Plan (GRAP) to combat pollution levels,

Delhi's air quality index receded to the poor range on Sunday, aided by consistent winds and less moisture, after a Saturday with a sever AQI score.The air quality index (AQI) was 348 at 11am, fell to 323 by 3pm and was 308 by 6pm.

Experts said even though winds were predominantly calm on Saturday, they picked up late in the evening, with similarly strong winds recorded on Sunday.