Air quality in the national capital continued to be in the poor category with the AQI clocking 320 at 9 am on Friday, the Central Pollution Control Board (CPCB) data showed.

The city's 24-hour air quality index (AQI) stood at 361 on Thursday.

Neighbouring Faridabad (283), Gurugram (287), Noida (304) and Greater Noida (286) also recorded their air quality in the poor category, while Ghaziabad, with an AQI of 309, was in the very poor category.

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 minimum temperature in the national capital was 9 degrees Celsius, normal for this time of the season, the India Meteorological Department (IMD) said.

While the maximum temperature is likely to settle at 24 degrees Celsius, the relative humidity recorded by the weather department at 8.30 am was 92 per cent.

On Thursday the minimum temperature at Safdarjung weather station was 8.4 degrees Celsius a notch below normal for this time of the year -- and the maximum temperature was 23.5 degrees Celsius, a notch below the season's normal, according to IMD data.