Thursday deluge pushes Delhi past yearly rainfall quota, four months early

India Meteorological Department (IMD) data showed that Delhi’s yearly total has now touched 818.1mm, surpassing the long-period annual average of 774.4mm

The national capital was lashed by its fifth “heavy” rainfall spell of the year on Thursday, pushing August into the “excess” category and propelling Delhi past its annual rainfall average, with more than four months to spare. India Meteorological Department (IMD) data showed that Delhi’s yearly total has now touched 818.1mm, surpassing the long-period annual average of 774.4mm.

With Thursday’s downpour, Safdarjung — the city’s base weather station — logged 13.1mm of rain in the 24 hours till 8.30am, followed by 79.4mm over the next nine hours. (Parveen Kumar/HT Photo)

With Thursday’s downpour, Safdarjung — the city’s base weather station — logged 13.1mm of rain in the 24 hours till 8.30am, followed by 79.4mm over the next nine hours. This took August’s total to 254.8mm, well above the monthly normal of 233.1mm. Officials said light rain is likely to persist until at least August 20, with two to three spells expected on Independence Day.

This is the fastest Delhi has crossed the annual mark since 2021. In the last two years, the milestone was reached in August — on the 30th in 2024 and the 20th in 2023. In 2022, it was crossed on October 10, while in 2021 it happened as early as August 1.

Mahesh Palawat, vice-president at Skymet, attributed the latest spell to the monsoon trough moving south of Delhi. “When the trough passes close to an area, it leads to cloud formation and subsequent rain. With easterly winds persisting and a low-pressure area in place, we will continue to see scattered light to moderate rain in Delhi over the next three to four days,” he said, adding that the trough is expected to remain south of Delhi for at least the next week.

Delhi’s rain this year has been remarkable for its consistency after a dry start — just 10.5mm in the first four months. Since May, the city has received more than 800mm, with every month recording excess rainfall. May was the wettest on record at 186.4mm, over six times the monthly normal of 30.7mm. June saw 107.1mm, 45% above average, while July logged 259.3mm, 24% higher than normal.

Palawat said that unlike last year, when La Niña conditions drove the monsoon, this year’s neutral conditions have been accompanied by several active weather systems over northwest India, bringing regular spells of rain in delhi-NCR and other parts of the region.

For Safdarjung, Thursday was only the fifth “heavy” rainfall spell of the year — classified as 64.5mm to 115.5mm in a 24-hour period. The others were 77mm on May 2, a season-high 81.4mm on May 25, 68.1mm on July 29, and 79mm on August 9.

On Thursday, most stations recorded moderate rain, with some logging heavy showers. Palam registered 49.4mm till 8.30am and another 45mm in the following nine hours; Lodhi Road saw 12.6mm and then 66.8mm; Ayanagar got 57.4mm and then 66mm; Ridge recorded 17.4mm and then 37.2mm; and west Delhi’s Pusa logged 5mm and then 49mm.

The IMD classifies rainfall as “light” when it is up to 15.5mm, “moderate” when it is between 15.6 and 64.4mm, “heavy” when it is between 64.5mm and 115.5mm and as “very heavy” when it is over 115.5mm in a 24-hour window.

The rain kept temperatures well below normal — the maximum at 27.7°C, six degrees below average, and the minimum at 23.6°C, three degrees below average. The IMD forecast for Friday is a maximum between 31°C and 33°C, and a minimum between 23°C and 25°C.

The showers also cleared Delhi’s air, with the 24-hour average air quality index improving from 120 (moderate) on Wednesday to 90 (satisfactory) on Thursday.