New Delhi, Dec 30 : Despite a thin layer of fog, the Delhiites witnessed respite in the cold as the mercury crossed the minimum temperature of 10 degree Celsius. The temperature was 11 degrees Celsius at Safdarjung observatory and 12 degrees Celsius in the Palam area during early morning hours, as per the India Meteorological Department (IMD). Despite the relief from chilly weather, the air quality in the national capital remained in a very poor category as the overall Air Quality Index (AQI) of the city reached 364 on Friday morning, according to data from the System of Air Quality and Weather Forecasting And Research (SAFAR). The AQI at Dhirpur entered into a severe category with PM 2.5 at 356, under a very poor category. Experts said that the air quality may also remain in a very poor category on Saturday. The 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'. In Pusa, the AQI recorded PM 2.5 at 373 'very poor category'. At Lodhi Road, the Air Quality Index with PM 2.5 concentration was at 360 under the very poor category and the PM 10 stood at 280 under the poor category. In Ayanagar the PM 2.5 was at 355, poor category while the PM 10 reached 277, in poor category. /IANS