A thick blanket of fog engulfed the national capital on Friday morning, as visibility dropped to zero in some areas, with the weather department predicting cloudy skies for the day.
The minimum temperature in Delhi was recorded to be 7 degrees Celsius, the India Meteorological Department (IMD) said.
The weather office said Delhi's IGI Airport experienced very dense fog, with visibility recorded at 0 metres. It said all runways are operating under CAT-III norms -- a navigation system that helps planes land under low visibility.
At 8 am, Palam weather station reported very dense fog with 0 metres visibility and calm winds over the past two hours, while the city's primary weather station, Safdarjung, reported visibility of 50 metres with calm winds, according to a weather department official.
Delhi's air quality was in the "very poor" category, with an AQI reading of 351 at 9 am. The humidity was recorded at 100 per cent at 8.30 am.
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".
The weatherman has predicted very dense fog for Friday, with the maximum temperature expected to settle around 17 degrees Celsius.