New Delhi: Thick fog sent visibility levels tumbling in the capital this morning but air services operated as per normal schedule, while some long distance trains were delayed.

General visibility dipped to 100 metres in several parts of the city affecting traffic movment. Cars moved slowly in the early hours of the day with fog lamps on and tail lights on the blink mode.

"However, air traffic remained unaffected as Runway Visibility Range at the Indira Gandhi International Airport was 900 meters at 8:30 a.M., "an airport spokesman said.

Some early morning trains coming to the capital were delayed due to foggy weather.

Minimum temperature in the capital was 9.4 degrees celsius, a notch above normal, the Met office said.

The weatherman attributed the gathering of fog to the south-westerly winds that brought moisture to the capital.

"South westerlies blowing due to a western disturbance over the capital have brought in moisture which led to formation of fog," he said.

The foggy conditions are likely to continue for another day, the weather office said.

At the airport, low visibility procedures were implemented at 8:00 a.M. And flights operated using the Instrument Landing Systems.

The western disturbance had led to a rise in temperatures in the capital which experienced the second warmest Republic Day yesterday in the last five years.

While morning temperature stood at a maximum of 22 degrees celsius, the maximum temperature for the day was 29 degrees celsius, seven degrees above normal.