The air quality index (AQI) in the national capital on Saturday morning was recorded under 'severe' category, the Central Pollution Control Board (CPCB) said.

The AQI in the national capital was recorded at 447, which comes under the ‘severe’ category.

An Air Quality Index (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’, 401 and 450 'severe’ and above 450 ‘severe-plus’.

The Centre on Friday ordered a ban on non-essential construction work and plying of BS-III petrol and BS-IV diesel four-wheelers in Delhi-NCR amid worsening AQI in the region.

Unfavourable meteorological conditions, including fog and haze, with low wind speed are the major causes behind this sudden spike in Delhi's daily average AQI, the Commission for Air Quality Management (CAQM), a statutory body responsible for formulating strategies to combat pollution in the region, said.

Re-invoking curbs under Stage-III of the Graded Response Action Plan (GRAP), the CAQM ordered a ban on non-essential construction work, stone crushing, and mining in Delhi-NCR.

Under Stage-III, restrictions are also imposed on the operation of BS-III petrol and BS-IV diesel four-wheelers in Delhi, Gurugram, Faridabad, Ghaziabad, and Gautam Budh Nagar.

The city recorded a minimum temperature of 9.6 degrees Celsius, two notches above the season's average, according to the India Meteorological Department (IMD).

The IMD has predicted a moderate fog during the day. The maximum temperature is likely to settle around 23 degrees Celsius, it said.

The relative humidity at 8.30 am was 97 per cent.

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