Dry spell, slow winds push Delhi’s AQI to 62-day high

According to IMD forecasts, Delhi is likely to see “no rain” over the next week with clear skies between Monday and Friday.

The air quality index (AQI) in the Capital sharply deteriorated on Sunday, recording the worst reading in 62 days. Lack of rain, slow wind speed, and localised emissions have led to relative increase in the pollution levels, officials said. Meanwhile, the India Meteorological Department (IMD) forecast said the city is not likely to witness any rain activity over the next week as monsoon begins withdrawing from the region.

Delhi saw relatively cleaner air quality over the last month owing to monsoon rains and high wind speeds. (Representative Image (File Photo/ANI))

The city noted an average AQI of 160 (higher end of the “moderate” zone), according to the Central Pollution Control Board (CPCB)’s 4pm reading. It continued to deteriorate further in the night, recording at 165 at 10pm.

This was the highest since July 19, when it stood at 171 (moderate).

Delhi AQI

To be sure, the city has dipped into the “moderate” category several times since. The city had recorded an AQI of 88 on Friday, 118 on Saturday, and 160 on Sunday with PM2.5 and Ozone being dominant pollutants.

Delhi saw relatively cleaner air quality over the last month owing to monsoon rains and high wind speeds. In September, Delhi has registered 12 “satisfactory” and eight “moderate” air quality days with Sunday facing the maximum pollutant load.

On July 9, Delhi recorded its cleanest air day of the year, with the AQI falling in the “good” category at 48. The last poor air quality day was registered on July 12 with AQI at 246.

A brief deterioration in AQI on July 12 and 13 was observed which was attributed to long-range transnational winds carrying mineral dust from storm activity in Afghanistan, Iran and Pakistan, which moved towards northwestern India, including Delhi, leading to elevated PM10 concentrations.

Delhi weather, IMD forecast

According to IMD forecasts, Delhi is likely to see “no rain” over the next week with clear skies between Monday and Friday and partly cloudy sky over the weekend. The normal date for the withdrawal of the southwest monsoon from Delhi is September 25. The IMD forecast says that the city will witness maximum temperature between 34-36°C and minimum temperature between 23-25°C over the next week.

Mahesh Palawat, vice-president at Skymet Weather, the monsoon is already in withdrawal phase and westerly winds have started. “It will gradually withdraw from Delhi. It is unlikely that there will be any further monsoon rain in Delhi. A brief depression may form in the Bay of Bengal but its impact in Delhi will be very limited.