New Delhi, Jan 2 (IANS): The residents of the national capital on Sunday woke up to a cold morning with the minimum temperature settling at 5 degrees Celsius. The people however, continued to breathe polluted air, as the Air Quality Index (AQI) was 323 for PM10 and 210 for PM2.5.

As the PM10 went over 300, the System of Air Quality and Weather Forecasting And Research (SAFAR) has issued a health advisory stating that sensitive people should consider reducing prolonged or heavy exertion and heavy outdoor work.

The PM2.5 level was under the 'very poor' category.

Usually, the air quality is categorised as 'good' when the AQI is between 0 to 50; 'satisfactory' between 51-100; 'moderate' between 101-200; 'poor' between 201-300; 'very poor' between 301-400; 'severe' between 401-500; and 'hazardous' at over 500.

As the day progresses, the weather agency has predicted a mainly clear sky with shallow fog in some areas.

The maximum temperature is likely to hover around 21 degrees Celsius and the minimum may remain steady at 5 degrees.

According to the morning update, a temperature of 5 degrees Celsius was recorded at 8.30 a.m. with a relative humidity of 94 per cent.

The city observed sunrise at 7.15 a.m. and the sun is likely to set at 5.37 p.m.

In the past 24 hours, the maximum temperature was recorded at 20.2 degrees Celsius, a notch above normal, and the minimum was 5 degrees.