Delhi continued to reel under cold to severe cold conditions with the maximum temperature settling two notches below the season's average at 18.3 degrees Celsius.
The Air Quality Index (AQI) in the national capital slipped to 'severe' category with a reading of 405 at 8 pm, according to the Central Pollution Control Board (CPCB).
The day began with a slight respite from the biting cold as the city recorded a low of 8.3 degrees Celsius, higher than 6.9 degrees Celsius on Tuesday, according to the India Meteorological Department (IMD).
Dense fog is likely at isolated places in Delhi on Thursday morning, it said.
The national capital has experienced five cold days and five cold wave days in January so far, the highest in the past 13 years, the meteorological department said.
The city witnessed mainly clear skies with moderate fog in the morning. The humidity level oscillated between 79 per cent and 60 per cent, according to IMD data.
On Tuesday, the maximum temperature was noted at 19.5 degrees Celsius, one notch below the normal. The visibility improved at various observatories in Delhi late night, with Safdarjung recording a visibility of 500 metres and Palam recording 700 metres at 11.45 pm.
Delhi’s IGI Airport reported a visibility of 600 metres at 5.30 am on Wednesday.
Twenty-four Delhi-bound trains were delayed by one to six hours due to fog in parts of northern India, according to the Indian Railways.
Due to the dense fog prediction, the transport and aviation activities in the city are expected to remain affected on Thursday as well, the IMD said.
Meanwhile, the AQI recorded at 8 pm on Wednesday was 405, according to CPCB 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'.
The relative humidity at 8.30 am was at 97 per cent, the IMD said.
(With inputs from agencies)
