A record 119.3 mm rainfall pounded Delhi under the impact of cyclonic storm Tauktae and a western disturbance in 24 hours ending 8:30 am on Thursday, breaking all the previous records for May, the IMD said on Thursday.
This was double the previous record rainfall of 60 mm on May 24 in 1976.
The city had also recorded a maximum temperature of 23.8 degrees Celsius on Wednesday, 16 notches below normal and the lowest in the month of May since 1951, it said.
"A record 119.3 mm rain fell in Delhi between 8:30 am on Wednesday and 8:30 am on Thursday, which is a new record for May," an Kuldeep Srivastava, the head of India Meteorological Department's regional forecasting Centre said.
The Lodhi road weather station recorded 124.4 mm rainfall during the period.
Palam, Ayanagar, Najafgarh and SPS Mayur Vihar gauged 64 mm, 98 mm, 92.5 mm and 95.5 mm rainfall.
Rainfall recorded below 15 mm is considered light, between 15 and 64.5 mm is moderate, between 64.5 mm and 115.5 mm is heavy, between 115.6 and 204.4 is very heavy. Anything above 204.4 mm is considered extremely heavy rainfall.
The rainfall in Delhi, Uttar Pradesh, northern Rajasthan, Himachal Pradesh and Uttarakhand on Wednesday was a result of interaction between the remnant of cyclonic storm Tauktae and a western disturbance, the IMD said.
R K Jenamani, senior scientist, national weather forecasting centre, said, "May remains generally dry. Normally, Delhi gets maximum of 30 mm or 40 mm (24-hour rainfall) in this month. The rain lasts only an hour or less. But this is completely different system coming from Arabian Sea and meeting with a western disturbance. Because the feature is rarest, so this much rain is not a surprise."
The IMD said "rainfall activity is very likely to decrease" on Thursday and "scattered to fairly widespread" rainfall is forecast in the capital.
The incessant rains brought the maximum temperature down to 23.8 degrees Celsius at Safdarjung on Wednesday. The minimum temperature on Thursday settled at 19.3 degrees Celsius, seven notches below normal.
"Safdarjung recorded a maximum temperature of 23.8 degrees Celsius on Wednesday. This is the lowest maximum temperature since 1951," Srivastava said.
In between, a low of 24.8 degrees Celsius was recorded on May 13 1982, he said.
According to the IMD, Delhi's maximum temperature on Wednesday was less than that of Srinagar (25.8 degrees Celsius) and Dharamshala (27.2 degrees Celsius) up in the north.
