Delhi got over 2.5 times the rain it usually does in past 3 months: Met

In March, April and May this year, Delhi received more than two-and-a-half times the rain it normally does, showed data from the India Meteorological Department (IMD), largely keeping the usual summer sizzle at bay. Experts attributed this unusual rain pattern to the increased frequency of western disturbances in the region over the past three months.

Delhi received an average of 143.7mm rain in these three months, as against the long-period average (LPA) of 56.6mm for this period. The Met department categorised this in the “large excess” zone.

In fact, seven of Delhi’s nine weather districts logged rain readings in the “large excess” zone. Of the two exceptions, rainfall was “excess” in north-east district, and “normal” in west Delhi.

IMD categorises rainfall between -99% and -60% as “large deficient”, between -59% and -20% as “deficient”, between -19% and 19% as “normal”, between 20% and 59% as “excess”, and over the 60% mark as “large excess”.

The Safdarjung station, Delhi’s base weather station, received 53.2mm rain in March, over three times the LPA of 17.4mm. Showers in April were just above normal, with the city receiving 20.1mm rain, as against the normal mark of 16.3mm. May was a particularly wet month for the city, with 111mm of rainfall eclipsing the monthly normal of 30.7mm.

This was in sharp contrast to last year when Safdarjung recorded no rain in March, 0.3mm in April, and 47.7mm in May.

Experts attributed this year’s showers to increased frequency of western disturbances seen in recent weeks.

IMD scientist Kuldeep Srivastava said, “Delhi recorded five western disturbances in May, and four each in April and March, bringing excess rain to the Capital. Normally, we see two or three western disturbances in March, three to four in April, and one or two in May,” he said.

The upshot of this rain has been an unusually cool summer so far, with temperatures well below normal for much of April as well as May, which is traditionally the Capital’s hottest month.

The average maximum temperature this March was 30.9°C, as compared to a normal of 29.9°C. In April, this went to 35.3°C, lower than the normal of 36.6°C. May saw this number settle at 36.8°C, which was 3.1°C below normal, with several spells of rain keeping Delhi’s characteristic sweltering summer in check and sparing the city any heat waves all month (it usually sees two to four).

Mahesh Palawat, vice president at Skymet meteorology, a private weather forecaster, said while February was fairly dry, a series of western disturbances have affected the Capital from March onwards.

“This year seems to be an exception, as such frequent activity, particularly western disturbances hitting northwest India back-to-back in May, is rare. While they move higher up in latitude by May, this year we have seen five of them hit Delhi in May alone, in turn bringing more rain,” he said.