New Delhi, Dec 18 (IANS): The national capital experienced a chilly and foggy Thursday, and over 20 trains and several flights were affected. Friday is expected to see similar weather, the Met Office said.

According to an official of the Northern Railway, 15 trains coming to Delhi were delayed due to fog while nine were rescheduled till 5 p.m.

Six flights were diverted, said an official of the Indira Gandhi International Airport.

However, no respite was likely Friday and the morning will see "moderate to dense" fog, the India Meteorological Department (IMD) said.

"There will be moderate to dense fog tomorrow (Friday) morning. The day would be cloudy and chilly," an IMD official said.

The maximum and minimum temperatures were likely to hover around 18 and 8 degrees Celsius, respectively.

Thursday's maximum temperature settled five notches below the season's average at 17.6 degrees Celsius while the minimum was 7.4 degrees Celsius, a notch below average.

The day's maximum humidity was recorded at 97 percent.

Wednesday's maximum temperature was 19.6 degrees Celsius, three notches below the season's average, while the minimum was 9.2 degrees Celsius, slightly above average.