The India Meteorological Department data showed that Delhi received 74 mm of rainfall in 24 hours ending 8:30 am on Sunday, the second highest precipitation on a day in October since 2007. In 2021, the Capital had logged 87.9 mm of rainfall on October 18.
The IMD said the ceaseless spell of rain brought down the difference between minimum temperature (20.8 degrees Celsius) on Friday and maximum temperature (23.4 degrees Celsius) on Saturday to 2.6 degrees Celsius -- the lowest since 1969. Earlier, the lowest such margin was recorded on October 19, 1998 at 3.1 degree Celsius, the IMD added.
The Safdarjung Observatory, Delhi's primary weather station, recorded another 7.4 mm of rainfall between 8:30 am and 5:30 pm on Sunday. The Palam observatory recorded 64.9 mm of rainfall in 24 hours ending 8:30 am. The Lodhi Road, Ridge, and Ayanagar weather stations received 87.2 mm, 60.1 mm, and 85.2 mm rainfall respectively, the IMD said.
The difference between minimum temperature (20.8 degrees Celsius) on Friday and maximum temperature (23.4 degrees Celsius) on Saturday was 2.6 degrees Celsius -- the lowest since 1969, an IMD official said.
The incessant rain in the capital also yielded the second "good" air quality day of the year, with the 24-hour average air quality index settling at 48. Delhi had recorded a 24-hour average AQI of 47 on September 16.
The Safdarjung Observatory, Delhi's primary weather station, recorded another 7.4 mm of rainfall between 8:30 am and 5:30 pm on Sunday.
The current rains in Delhi are not monsoon showers, which had receded from the city on September 29 after giving 516.9 mm of rainfall against a normal of 653.6 mm, the IMD said. According to the Met department, the interaction of a western disturbance, which lies as a trough in mid and upper air, with a deep trough of easterly wind at a lower level led to the post-monsoon rain in the Delhi-NCR region.
Mahesh Palawat, vice president (meteorology and climate change), Skymet Weather, said easterly winds brought moisture from the Bay of Bengal with a trough running from Andhra Pradesh to northwest Uttar Pradesh.Easterly winds carried moisture from the Arabian Sea due to another trough extending from Delhi to east Rajasthan.
"In October to March, we get 3 to 5 such intense interactions," an IMD official said. Palwat said these weather systems will weaken over the next two-three days. Sporadic light to moderate rain is likely on Monday, but not much precipitation is expected the day after, he said.