Most places in the city recorded soaring levels of PM 2.5 pollutant which were either in "very poor" or "poor" category on Thursday.

Air quality in Delhi turned "severe" from "very poor" well above the prescribed limits. According to the Central Pollution Control Board (CPCB), the Air Quality Index (AQI) for Delhi remained "severe" with the index value 420.

System of Air Quality and Weather Forecasting & Research (SAFAR) showed the level of particulate matter 2.5 - which can travel deeply into the respiratory tract down to the lungs - at 438 micrograms per cubic metre at Delhi University in north Delhi, it was 419 micrograms per cubic metre at Pitampura in west Delhi and 447 micrograms per cubic metre at Mathura Road.

However, at Lodhi Road in south Delhi the level of PM 2.5 remained 339 as it was on Thursday and categorised as "very poor".

At the pollution measuring centres of CPCB including Anand Vihar in east Delhi, Punjabi Bagh in the west, R.K. Puram in the south and Mandir Marg in central Delhi the average value of PM 2.5 pollutant was 454, 437, 419 and 414 micrograms per cubic metre.

Dwarka in west Delhi had a marginally lower level of PM 2.5 recorded at 366 which falls under "very poor" category.

PM 2.5 is produced by burning fuels and its level above 400 is considered "severe".

On its part, the Delhi government has intensified efforts at vacuum cleaning and washing of city roads to curb pollution due to dust. It has also stopped all construction and demolition activities.

According to the weather office, the maximum temperature on Friday settled at 30.1 degrees Celsius, one notch above the season's average whereas the minimum temperature was recorded at 11.5, three notches below the season's average.

"The sky will remain clear on Saturday but mist or shallow fog would occur in the morning. The maximum and minimum temperatures would be around 30 and 14 degrees Celsius respectively on Saturday," an India Meteorological Department (IMD) official said.