Rain inundates Delhi, highest in September in 19 years, IMD data shows

Delhi recorded 112.1 mm rainfall in 24 hours ending at 8:30 am on Wednesday, the highest single-day precipitation in September in 19 years, according to India Meteorological Department (IMD).

The capital had recorded 126.8 mm rainfall on September 13, 2002. The all-time record is 172.6 mm rainfall on September 16, 1963.

The heavy burst of rain submerged several areas, including the diplomatic enclave of Chanakyapuri, in knee-deep water and affected traffic movement in parts of the city.

The city gauged 75.6 mm rainfall in just three hours starting 8:30 am.

This means that Delhi has already recorded more than the monthly quota of rain on the first two days of the month.

On an average, the capital gauges 125.1 mm precipitation in September every year, according to the IMD.

Asked if the IMD expected such heavy rainfall -- 187.1 mm since 8:30 am on Tuesday, an official said it is difficult to make "precise predictions" for a small area like Delhi two to three days in advance.

"The predictions are for larger areas, say like Haryana and Punjab. This applies across the world," he said.

Mahesh Palawat, Vice President, Skymet Weather, a private forecasting agency, said the monsoon pattern is changing due to climate change.

"The number of rainy days has reduced over the last four to five years, and there has been an increase in extreme weather events," he said

"We have been recording short and intense bouts of rains, sometimes around 100 mm rainfall in just 24 hours. In the past, this much precipitation would occur over a period of 10 to 15 days," he said.

Officials at the India Meteorological Department said the Safdarjung Observatory, considered the official marker for the city, gauged 112.1 mm rainfall in the 24 hours ending 8:30 am on Wednesday, the highest on a day in September in 19 years.

The weather stations at Lodhi Road, Ridge, Palam and Ayanagar recorded 120.2 mm, 81.6 mm, 71.1 mm and 68.2 mm rainfall, respectively, in the 24 hours ending 8:30 am.

Since 8:30 am, Palam, Lodi Road, Ridge and Ayanagar have recorded 78.2mm, 75.4mm, 50mm and 44.8mm rainfall, respectively, it said.

On Tuesday, Delhi gauged 84 mm rainfall in just six hours -- between 8:30 am and 2:30 pm -- that flooded roads and led to massive traffic snarls on key stretches such as ITO, Ring Road near IP Estate flyover, Dhaula Kuan, and Rohtak road.

"The intensity is likely to reduce. Another spell of rain is likely from September 7," an IMD official said.

In its forecast for the month of September, the IMD said, "Normal to below normal rainfall is most likely over many areas of northwest."

The Delhi Traffic Police issued an advisory against traffic obstruction at Mother Teresa Crescent Marg, Mayapuri Chowk, Ghitorni Metro Station to MG Road and Adchini towards Kishangarh due to the heavy waterlogging.

Weather experts said such spells of rain do not help recharge groundwater and lead to flooding in low-lying areas.

The water percolates in the ground if it rains slowly over four to five days. In case of heavy falls, the rainwater runs off quickly, Palawat said.

"The rain washes away pollutants, but since the number of rainy days has reduced, the average annual air quality is also getting affected," he said.