New Delhi: Delhi's air quality deteriorated to the very poor category on Thursday morning due to calm winds and cool weather conditions even as the city's minimum temperature settled at 15 degrees Celsius, two notches below the normal. The Air Quality Index (AQI) stood at 333 at 8.10 am, deteriorating from 262 on Wednesday morning.

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On Tuesday, the AQI was 303 at 4 pm while it was 312 at 4 pm on Monday, the day of Diwali, Central Pollution Control Board (CPCB) data showed. 

Delhi's Anand Vihar monitoring station recorded an AQI in the severe category with an index value of 405 at 8.10 am on Thursday. 

Among the monitoring stations that recorded very poor air quality were Wazirpur (386), Patparganj (360), Vivek Vihar (316), Punjabi Bagh (328) and Jahangirpuri (380).  Delhi's neighbouring cities of Ghaziabad (338), Noida (331), Greater Noida (328), Gurugram (334) reported very poor air quality. Faridabad recorded poor air quality with index value of 300.  

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. 

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Weather officials said that the air quality deteriorated in the city because of calm wind conditions and cool weather allowing the accumulation of pollutants.

According to the India Meteorological Department (IMD), the day will remain clear and the maximum temperature on Thursday will hover around 32 degrees Celsius. 

The maximum temperature on Wednesday settled at 32.3 degrees Celsius, a notch above normal.  

Relative humidity at 8.30 am was 84 per cent, the weather office said.

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