NEW DELHI: The weather department on Friday issued a "cold-day" alert and said "dense to very dense fog" is likely to be witnessed in Delhi-NCR for the next two days.
The maximum temperature of the national capital settled at 19.8 degrees Celsius on Friday, a notch below the season's average.
Trains and flights are operational, but transportation was impacted due to dense fog in the city.
Train services were impacted due to the fog for the third day, with 11 Delhi-bound trains delayed.
"Fog conditions at IGIA (Indira Gandhi International Airport) improved significantly in the morning, with the lowest visibility at 150 metres in dense fog," the India Meteorological Department (IMD) said.
The minimum temperature was recorded at 10.7 degrees Celsius, four notches above the season's average.
The IMD has said there is a high probability of a "cold wave" in isolated pockets of Delhi, starting from the second week of January.
The weather department indicates a substantial likelihood, ranging from 68 to 100 per cent.
"Cold-day conditions are very likely in some to many parts of Delhi on December 30 and 31," the IMD said.
Humidity levels oscillated between 84 per cent and 100 per cent.
The 24-hour average Air Quality Index (AQI) was recorded at 382, in the "very poor" category, at 4 pm.
The maximum and minimum temperatures are likely to hover around 19 and 10 degrees Celsius respectively on Saturday.
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".