India, Dec. 26 -- After a brief respite, Delhi's air quality deteriorated to the "very poor" category on Friday as wind speeds dipped again and also led to a marginal rise in the minimum temperature to 7.7degC. The mercury on Thursday dipped to 6.5degC and was likely to settle between 5-8degC until Monday, before another western disturbance was expected to influence the region and raise the minimum temperatures.

Dense to very dense fog was also likely soon after, as wind speeds dip. A 24-hour average air quality Index (AQI) of 305 (very poor) was recorded at 8am on Friday, compared to 234 (poor) at 4pm on Thursday, 271 (poor) on Wednesday, and 412 (severe) on Tuesday. Strong winds up to 20 kilometres per hour helped improve Delhi's AQI t...