Dense to very dense fog swept over parts of the country's north and northwest on Monday with the Met department predicting the conditions to persist over the next few days.A severe cold wave gripped the region with temperatures plummeting in several towns and cities.In Delhi, dense fog lowered visibility to 50 metres in some areas, affecting road and rail traffic.

from Times of India https://timesofindia.indiatimes.com/business/india-business/dense-fog-cold-wave-grip-swathes-of-north-northwest-india/articleshow/96521346.cms