Fog persisted through the early hours of Sunday morning even though the Regional Weather Forecasting Centre (RWFC) had expected it subside.
Visibility dropped to 50m at 5:30 am, and peaked at 1800m at 5:30 pm.
A scientist at the RWFC had earlier said that climactic conditions, such as the movement of western disturbances and associated induced cyclonic circulation, were expected to bring westerly winds from Sunday.
This was expected to help lift some of the fog; they now expect it to get better from Monday.
“Of course there will be fog; it will not completely go away. But the intensity of the fog will reduce, and it will get better on December 13 and 14 (Tuesday and Wednesday),” said the scientist.
India Meteorological Department officials at the Indira Gandhi International Airport corroborated these claims, and suggested the spell of dense fog would be weakened by Monday morning, or latest by Monday night.
The dense fog on Sunday delayed 90 inbound trains, while 28 trains had to rescheduled and four others had to be cancelled.
Though few domestic flights had been delayed at the Delhi airport, officials maintained that flight operations had not been drastically affected.
Flights are usually affected only when visibility drops below 200m.
The RWFC said Delhi would experience moderate to dense fog on Monday, with the maximum and minimum temperatures expected to be 25 and 11 degrees, respectively.