Record single-day August rain for Delhi, highest in 14 years

New Delhi: After a 10-day long, hot, dry spell, the national capital on Saturday received 138.8mm rain in 24 hours, the highest single-day rainfall recorded in August in 14 years and the ninth highest since 1961 during the month, showed the India Meteorological Department’s (IMD) rainfall records.

The heavy showers and thunder activity that hit the city early Saturday morning submerged key stretches and major underpasses, including Minto Bridge in central Delhi, throwing traffic out of gear.

According to IMD officials, between 8.30am on Friday and 8.30am on Saturday, the Safdarjung observatory received 138.8 mm rainfall. The city received a bulk of its rainfall during the spell — the heaviest so far this season — between 2.30 am on Friday and 8.30 am on Saturday, when it rained continuously for six hours.

IMD records show that previously Delhi received such a heavy 24-hour spell during the month on August 2, 2007, when the city got 166.6mm rainfall. The highest-ever single-day rainfall recorded during this month was on August 2, 1961 (184mm).

“Today’s record is also the ninth highest single-day rainfall since 1961. It is mainly because of a cloud belt passing through the northern and central parts of Delhi. The thunder activity and lightning was primarily on its account. Light rain activity is expected to stay till August 23,” said RK Jenamani, senior scientist, IMD.

The wet spell, however, is likely to be over soon, said weather officials, and the last week of August is likely to be mostly dry.

While this August has mostly been dry, with a 10-day break phase, Saturday’s spell has nearly covered the rain deficit for the month. With Saturday’s rain, the total rainfall received this month is 202mm. The normal rainfall count for the month is 247.7mm.

August is usually Delhi’s wettest month.

Delhi saw a long dry spell with above normal temperatures between August 9 and August 19 because of monsoon’s break phase in northwest India. Before this, Delhi received 15.4mm of showers on August 8.

“The monsoon trough was close to Delhi and with a cloud belt passing through its northern and central parts, heavy rainfall occurred in Delhi. This is going to lead to a significant drop in temperatures. Light to moderate showers are expected on Sunday as well. Patchy rainfall will continue till August 23. However, from August 24, the weather again is likely to go dry for at least four or five days, as the trough is again expected to shift away from northwest India,” said a senior IMD official.

On Saturday, the maximum temperature was 32.6 degrees Celsius, a notch below the season’s average. The minimum settled at 23.8°C, three notches below normal for this time of the year.

Mahesh Palawat, president, skymet, a private forecaster said that a cyclonic circulation built over east Rajasthan and the trough was also in Delhi’s vicinity, which resulted in Saturday’s heavy spell. “However, weather is again likely to go dry from August 25 to August 30, because of the trough likely to shift to the Himalayan foothills once again,” said Palawat.