Dense fog enveloped Delhi with visibility dropping to zero early Wednesday, as the minimum temperature dropped sharply to 7.4 degrees Celsius, the weather office said.
"Palam's visibility dropped to 50 metres at 12 midnight. It improved to 500 metres by 2.30 am, before dropping to zero at 5.30 am. Winds remained westerly at 5-7 kmph throughout the night," the India Meteorological Department (IMD) said.
The minimum temperature in Delhi dropped to 7.4 degrees Celsius, 0.5 notch above normal, from 10.5 degrees Celsius on Tuesday, according to the IMD.
The maximum temperature in Delhi is expected to settle around 16 degrees Celsius on Wednesday, the weather office said.
The capital's Air Quality Index (AQI) was recorded at 334 at 9 am, dropping to 'very poor' category from the 'poor' AQI recorded on Tuesday, Central Pollution Control Board data showed.
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'.