New Delhi, Jan 15 (PTI) Delhi's minimum temperature rose to 6.4 degrees Celsius, a notch above normal, on Friday due to partly cloudy weather, the India Meteorological Department (IMD) said.
The maximum temperature stood at 20.8 degrees Celsius, a notch above normal.
Moderate fog lowered visibility to 201 metres at Safdarjung and 300 metres at Palam in the morning, an IMD official said. Dense fog is predicted in parts of the city on Saturday.
According to the IMD, very dense fog is when visibility is between 0 and 50 metres. In case of dense fog, the visibility is between 51 and 200 metres, moderate at 201 and 500 metres, and shallow at 501 and 1,000 metres.
On Thursday, the Safdarjung Observatory, which provides representative data for the city, recorded a minimum of 2 degrees Celsius, five notches below normal. It was 3.2 degrees Celsius on Wednesday.
Cold and dry northerly/northwesterly winds from the western Himalayas brought the minimum temperature down in Delhi on Thursday. The wind direction then changed to northeasterly. This, along with partly cloudy weather, resulted in an increase in the minimum temperature, said Kuldeep Srivastava, the head of the IMD's regional forecasting centre.
On January 1, the city had recorded a minimum of 1.1 degrees Celsius, lowest for the month in 15 years.
The city's air quality remained severe on Friday as well. The air quality index had entered the severe zone on Thursday due to the prevailing extremely unfavourable conditions for dispersion of pollutants, government agencies.
The city's 24-hour average air quality index (AQI) was 460. It was 429 on Thursday, 354 on Wednesday, 293 on Tuesday and 243 on Monday.
An AQI between zero and 50 is considered good, satisfactory at 51-100, moderate at 101-200, poor at 201-300, very poor at 301-400, severe at 401-500.
Srivastava said the wind speed had slowed down and the moisture in the air had made the pollutants heavier.
The central government's air quality early warning system for Delhi said slow winds and ventilation conditions were 'extremely unfavourable' for dispersion of pollutants.
This will lead to further deterioration in air quality, the agency said. PTI GVS HMB