Overnight winds, showers cool Delhi, push AQI to ‘satisfactory’

Delhi’s AQI stood at 88 on Monday, a sharp drop from 175 (‘moderate’) a day earlier and the lowest since October 8 (80) last year

Strong overnight winds and scattered light showers cooled Delhi on Monday and sharply improved air quality, with the air quality index (AQI) dropping to 88 (satisfactory), the lowest it has been since last October.

Delhi’s maximum temperature, meanwhile, settled at 32.2°C, seven degrees below normal, even as no rain was recorded after 8.30am till Monday evening. It was 36.6°C a day earlier. (Raj K Raj/HT Photo)

The storm, driven by a western disturbance affecting the region, saw wind speeds touch up to 70km/hour between 11.30pm on Sunday and 12.30am on Monday. The winds disrupted flight operations at Indira Gandhi International Airport, with 24 flights diverted to nearby airports, officials said.

Delhi’s AQI stood at 88 on Monday, a sharp drop from 175 (‘moderate’) a day earlier and the lowest since October 8 (80) last year. This is also the lowest in the month of May in three years, since the 85 (‘satisfactory’) recorded on May 31, 2023.

The sharp improvement in air quality prompted the Commission for Air Quality Management (CAQM) to lift Stage-1 measures of the Graded Response Action Plan (GRAP) with immediate effect.

“The AQI of Delhi has shown significant improvement owing to rain and favourable meteorological conditions… Further, the forecast by IMD and IITM indicates that the AQI is likely to stay between ‘satisfactory’ and ‘moderate’ in the coming days,” CAQM said in a statement.

Stage-1, invoked on April 16, includes preventive measures such as increased water sprinkling, mechanised sweeping, and stricter enforcement against polluting vehicles and industries.

Delhi’s maximum temperature, meanwhile, settled at 32.2°C, seven degrees below normal, even as no rain was recorded after 8.30am till Monday evening. It was 36.6°C a day earlier.

The India Meteorological Department (IMD) said strong winds began affecting Delhi after 11.30pm on Sunday, with most parts recording light, scattered showers till 8.30am.

Data showed wind speeds touched up to 70km/hour at the Pusa station at 11.45pm on Sunday. This was followed by 54km/hour at Jafarpur at 11.30pm and 52km/hour each at Safdarjung (12.30am) and Pitampura (11.45pm).

“For Delhi, a red alert was issued for most parts till 1.30am and an orange alert for south-eastern Delhi. Strong winds were recorded first, followed by short bursts of rain that continued till morning,” an IMD official said.

Forecasts indicate Delhi is likely to see more rain late Monday night and in the early hours of Tuesday, while thundery development is expected on Wednesday before temperatures begin rising again.

The maximum is likely to hover between 32-34°C on Tuesday and 35-37°C on Wednesday, possibly rising to 40°C by Saturday as dry weather returns.

The minimum on Monday stood at 18.8°C, six degrees below normal. Nights are expected to remain relatively cool, with the minimum hovering between 18-20°C on Tuesday and 20-22°C on Wednesday. It is expected to rise from Thursday, reaching 23-26°C till Sunday.

Mahesh Palawat, vice-president at Skymet, said a cyclonic circulation remains over Rajasthan and will move south of Delhi, leading to the possibility of rain till Wednesday. “As is typical of pre-monsoon showers, we expect rain late at night or in the early hours, with the sun coming out again around noon,” he said.