Parts of Delhi witnessed very dense to dense fog on Friday morning while the minimum temperature settled at 9.4 degrees Celsius, according to the India Meteorological Department (IMD).
The weather office has forecast shallow to moderate fog and cold day conditions at a few places in the national capital during the day.
Very dense fog was observed in isolated pockets over Punjab and Delhi early in the morning. Dense fog enveloped parts of Delhi, the IMD said.
The Safardjung Observatory recorded a minimum temperature of 9.4 degrees Celsius, more than two notches above normal, at 8:30 am, it said.
However, the Ridge Observatory recorded a low of 9.1 degrees Celsius.
An orange alert has been issued for Delhi for the day with shallow to moderate fog and cold day conditions likely at a few places, officials said.
The visibility was 50 metres at Palam at 8:30 am.
At least 22 trains were running late due to poor visibility, according to information shared by railway officials.
On Thursday, Delhi recorded a minimum temperature of 7.7 degrees Celsius, a notch above normal, and a maximum of 12.5 degrees Celsius.
Delhi's Air Quality Index (AQI) stood at 352 (very poor) at 9 am on Friday, according to Central Pollution Control Board data.
An AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.