Delhi's air quality continues to be in poor category

Delhi's air quality continued to be in the poor category but is likely to improve with authorities forecasting increased wind speed.

The overall air quality index (AQI) for the national capital was recorded at 263, which falls in the 'poor' category. According to the Centre-run System of Air Quality and Weather Forecasting (SAFAR) also the overall Delhi air quality is still poor.

"It may improve as wind speed is sufficiently high. Wind speed continued to remain a key factor in improving the air quality. Temperature is not declining and there is good sunlight. However, humidity is still high and temperature is likely to cool. Both factors are unfavourable and push AQI to very poor," it said.

The overall PM2.5 (fine particulate matter in the air with a diameter of less than 2.5 micrometre) level was recorded at 119 and the PM10 (fine particulate matter in the air with a diameter of less than 10 micrometre) level at 210, SAFAR said.

The national capital recorded its best air quality in moderate category in over two months on Thursday after rains washed down pollutants before slipping into poor category on Friday.

On Saturday, four areas -- Jahangirpuri, Nehru Nagar, Wazirpur and R K Puram -- recorded very poor air quality while 24 recorded poor air quality and four moderate air quality, the Central Pollution Control Board said.

An AQI between 100 to 200 comes under moderate category, 201 and 300 is considered 'poor', 301 and 400 'very poor' and 401 and 500 'severe'.

Neighbouring Ghaziabad, Noida and Faridabad recorded 'poor' air quality, while Gurgaon recorded 'moderate' air quality, the CPCB data showed.

According to the Indian Institute of Tropical Meteorology, the maximum ventilation index is 3000 sqm/second on Saturday.

A ventilation index lower than 6,000 sqm/second with average wind speed less than 10 kmph are unfavourable for dispersion of pollutants.