NEW DELHI: Delhi residents on Thursday woke up to a surprising sight on May 4: a layer of fog blanketing the city, something that could have happened in 40 years. The Indian Meteorological Department said May 4 witnessed the coldest day after 1982 with a minimum temperature of 15.8 degrees C. On May 2, 1982, the minimum temperature was 15.2 degrees. The city recorded minimum temperature 15.1 degrees on May 2, 1969.
May is supposed to be the hottest month of the year with a mean maximum temperature of 39.5 degrees. So, the spell of ‘shadow fog’ was unusual and drew a range of reactions bordering on disbelief. Many residents said it was a ‘winter-esque morning’ in the middle of the peak summer.
Wednesday (May 3) was the capital city’s wettest day thus far. The Safdarjung weather station recorded 20.9 mm of moderate rainfall within nine hours yesterday — the highest single-day precipitation for Delhi.
The same day saw Palam getting drenched with 11.8 mm of rain, Lodhi Road 24.6 mm, Ridge area 14.6 mm, Ayanagar 13.8 mm, Mungeshpur 31.5 mm, Narela 9.5 mm and Pitampura 55.5 mm.
The daytime temperatures remained well below 30 degrees for the opening two days — 25.4 degrees on May 1 and 26.7 degrees on May 2. On Wednesday, the mercury rose to 30.6 degrees, but still remained 9 notches below the normal for this time of the year.
Wild variations
IMD says May 4 was the coldest day in Delhi after 1982 with a min temp at 15.8 deg C. On May 2, 1982, the minimum was 15.2 deg. And on May 2, 1969, the minimum was 15.1 deg
The rainfall episode also took Delhi’s rain figure for the month to 36 mm, surpassing May’s monthly average of 29.4 mm in just three days
The minimum temp of 15.8 deg was up to 9 degrees below average. It was the lowest May minimum temperature in a decade
Why the fluctuation?
It is triggered by a western disturbance (WD) impacting the weather across north and northwest India. Such WDs are essentially low-pressure systems that originate over the Mediterranean Sea and move westwards while gathering moisture, which then gets dumped over north India.