Delhi's experiences 'severe' air quality for third day on trot

The national capital's air quality was in the 'severe' category for the third day in a row on Thursday due to low wind speed and high humidity, authorities said.

The city's 24-hour average air quality index read 423 at 4 pm. On Wednesday, it was 407 and on Thursday 402.

Neighbouring Faridabad (452), Ghaziabad (411), Greater Noida (412), Gurgao (362) and Noida (412) also recorded their air quality in the "severe" category.

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'.

The Ministry of Earth Sciences' air quality forecast agency SAFAR said low ventilation and high humidity have led to such a situation. Similar conditions will further increase the AQI on Friday, it said.

According to the India Meteorological Department, the humidity levels oscillated between 61 per cent and 95 per cent.

Weather experts said the slowing down of winds due to a western disturbance affecting northwest India is leading to accumulation of pollutants and high moisture content in the air turns pollutants heavier, making dispersion difficult.

The wind speed will remain low in the coming days due to two back-to-back western disturbances. Light rain is likely in the plains of north India between December 27 and December 29 which may improve the air quality a bit.

Meanwhile, Delhi's minimum temperature increased marginally to 5.5 degrees Celsius while the maximum temperature settled at 23.1 degrees Celsius, two notches above the normal.