Cold conditions continued to prevail in the national capital with the minimum temperature settling at 4.6 degrees Celsius, three notches below the season's average.
According to railways, twenty-one trains were running late for up to five hours due to bad weather.
An official said the Bhubaneswar-New Delhi Rajdhani was delayed for five hours while the Malda-Delhi Farakka Express was delayed for four hours.
An official of the MeT department said the Safdarjung observatory recorded visibility at 300 metres at 8.30 am.
"The skies will remain partly cloudy and the maximum temperature is expected to settle at 20 degrees Celsius," the official said.
Delhi's air quality recorded at 9.38 am was 423 in the "severe" category.