Delhi air quality to improve as IMD predicts light rain on Sunday

The passing of the western disturbance also resulted in a marginal increase in the temperatures. On Saturday, the maximum temperature at the Safdarjung weather station was 32.8 degrees Celsius, a notch above the season’s normal

Delhi may look forward to improved air quality on Sunday with the India Meteorological Department (IMD) forecasting moderate rain over the city and a change in the wind direction.

A football game in progress at Shantipath in Chanakyapuri on Saturday. According to Central Pollution Control Board (CPCB) data on Saturday, Delhi’s overall air quality index (AQI) was 173, in the ‘moderate’ category. This was only marginally higher than Friday’s 170, also in the ‘moderate’ zone. (Arvind Yadav/HT PHOTO)

IMD officials said that under the impact of a western disturbance heavy rain and hailstorms were reported on Saturday from parts of Punjab, Haryana and Rajasthan. The western disturbance is also likely to cause moderate to light rains in parts of Delhi on Sunday, which is expected to improve the city’s air quality further, IMD scientists said.

A western disturbance is an extratropical storm originating in the Mediterranean region that brings sudden winter rain to the northern parts of the Indian subcontinent.

According to Central Pollution Control Board (CPCB) data on Saturday, Delhi’s overall air quality index (AQI) was 173, in the ‘moderate’ category. This was only marginally higher than Friday’s 170, also in the ‘moderate’ zone.

“The air quality is likely to improve over Sunday and Monday. The reduction in pollution levels has already started. Since the winds blowing into Delhi is from the southeast direction, the impact of stubble fires in Delhi’s pollution will be negligible—around 1-2%,” said VK Soni, head of IMD’s environment and research department.

Soni, however, warned that the impact of weather conditions will only be temporary, and from October 25 when the wind direction changes back to north-westerly, pollution levels will start rising again. The north-westerlies bring in highly polluting particulate matter from the stubble fires in the neighbouring Haryana and Punjab.

“Pollution levels will start rising again after October 25, but the AQI will remain in the moderate range,” Soni said.

The passing of the western disturbance also resulted in a marginal increase in the temperatures in the national capital. On Saturday, the maximum temperature at the Safdarjung weather station, considered the representative for the entire city, was 32.8 degrees Celsius, a notch above the season’s normal. The minimum temperature was 18.4 degrees Celsius, two degrees above what is considered normal for this time of the year.

At Palam, the maximum temperature was 32 degrees Celsius, and the minimum temperature was 20.6 degrees Celsius, three degrees above normal.

“There are chances of moderate to light rain in parts of Delhi on Sunday. While the temperature over the weekend has remained slightly higher because of the western disturbance, mercury levels will start dropping from next week,” said Mahesh Palawat, vice-president (meteorology and climate change) at Skymet Weather Services.

After this year’s first ‘good’ air day on Monday, followed by ‘satisfactory’ air on Tuesday, the air quality quickly rebounded sharply into the poor zone on Wednesday. However, till then, the air quality has stayed in the moderate category.