The minimum temperature in Delhi settled at 6.3 degrees Celsius on Thursday, three notches below the season's normal.
A senior MeT Department official said the maximum temperature was recorded at 20.4 degrees Celsius, three notches below the normal.
The weather office has forecast mainly clear skies with shallow fog in the national capital on Friday.
On Friday, minimum and maximum temperatures will settle around 7 and 21 degrees Celsius, respectively, it said.
The Air Quality Index at 7.30 pm was 227. An AQI between 0-50 is considered 'good', 51-100 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor' and 401-500 'severe'.