NEW DELHI, Nov 21: Air quality in many parts of Delhi and the National Capital Region turned severe on Thursday due to calm winds and high humidity, officials said.
The situation is likely to worsen in the next 24 hours, while some relief is expected on Saturday.
The overall air quality index (AQI) in the national capital was 361 at 1:30 pm on Thursday.
The AQI for Rohini (410), Anand Vihar (413), Nehru Nagar (403) and Bawana (404) entered the “severe” zone.
Neighbouring Ghaziabad (412) also recorded “severe” pollution levels, while the AQI in Greater Noida (395) and Noida (394) bordered “severe” zone.
An AQI between 201 and 300 is considered “poor”, 301-400 “very poor” and 401-500 “severe”.
According to the India Meteorological Department (IMD), very low wind speed due to a western disturbance and high humidity due to shallow fog in the morning led to accumulation of pollutants.
A senior IMD scientist said the air quality is expected to remain severe on Thursday and Friday. An expert at Skymet Weather, a private forecaster, said moderate winds from November 23 would bring some relief but it will be temporary as another western disturbance from November 25 will again cause the wind speed to dip.
“There are chances of good rain on November 25 and 26. If that happens, pollutants will be washed away. Otherwise, a long-term relief is expected only after November 28,” he said.
The Centre-run System of Air Quality Forecasting And Research also said that relief is expected only on Saturday with an increase in wind speed, which will disperse pollutants faster.
Meanwhile, Delhi recorded a minimum temperature of 12.5 degrees Celsius, normal for this time of year.
The humidity level recorded at 8.30 am was 89 per cent. (PTI)