Dense fog envelops Delhi, reduces visibility to 50m; 39 trains delayed

Dense fog cloaked Delhi on Tuesday morning, lowering visibility to just 50 metres and affecting road and rail movement.

An official of the India Meteorological Department (IMD) said the Palam observatory near the Indira Gandhi International Airport recorded a visibility level of 50 metres.

Thirty-nine trains were delayed by an hour to five-and-a-half hours due to the foggy weather, a Northern Railways spokesperson said.

Satellite images showed a dense layer of fog persisting over vast swathes of north India, extending from Punjab to Bihar across Haryana, Delhi and Uttar Pradesh.

According to the weather office, 'very dense fog' is when visibility is between 0 and 50 metres, between 51 and 200 metres is 'dense', between 201 and 500 metres 'moderate', and between 501 and 1,000 metres 'shallow'.

Delhi saw cold wave conditions for the fifth consecutive day on Monday. The season's longest fog spell has crippled road, rail and air traffic movement.

IMD officials said the Palam observatory recorded visibility levels below 1,000 metres from 8:30 pm on Sunday to 4:30 pm on Monday.

The Safdarjung observatory, Delhi's primary weather station, recorded a minimum temperature of 6.4 degrees Celsius.

With this, officials said, cold wave conditions in the national capital have abated.

The Safdarjung observatory has recorded minimum and maximum temperatures much below normal levels so far this month.

It logged a minimum temperature of 3.8 degrees Celsius on Monday, 1.9 degrees Celsius on Sunday, 2.2 degrees Celsius on Saturday, 4 degrees Celsius on Friday, 3 degrees Celsius on Thursday and 4.4 degrees Celsius on Wednesday.

Meteorologists attribute the long spell of intense cold to a large gap between two western disturbances, which meant frosty winds from the snow-clad mountains blew in for a longer-than-usual period.