Very dense fog blanketed parts of Delhi on Tuesday, reducing visibility to zero metres and affecting traffic movement, the India Meteorological Department (IMD) said. The minimum temperature dropped to 6.9 degrees Celsius as northwesterly winds from the snow-clad western Himalayas have started blowing towards the plains, an IMD official said. On Monday, Delhi's minimum temperature stood at 9 degrees Celsius, two notches more than normal, due to party cloudy weather and easterly winds which are not as cold as northwesterly winds.
The IMD said that very dense fog lowered visibility to zero metres at Palam at 8:30 am. Visibility level was 300 metres at Safdarjung.
According to the IMD, very dense fog is when visibility is between 0 and 50 metres. In case of dense fog, visibility is between 51 and 200 metres, moderate 201 and 500 metres, and shallow 501 and 1,000 metres.
