The India Meteorological Department (IMD) on Thursday announced that the southwest monsoon — which gave highly uneven rainfall this year — has withdrawn from Delhi.  The national Capital recorded an overall rain deficit of 19% this monsoon season. Up to 19 percent of deficient and excess rain is considered 'normal', according to the IMD.

Usually, the monsoon starts retreating from northwest India by September 17 and withdraws from Delhi within a week. The capital recorded 164.5mm of precipitation against a normal of 125.1 mm in September. "The southwest monsoon has withdrawn from Punjab; some parts of Jammu & Kashmir, Himachal Pradesh, west Uttar Pradesh, Haryana and Rajasthan and entire Delhi," IMD said. The Safdarjung Observatory, Delhi's primary weather station, logged 516.9 mm of rainfall this monsoon season, less than half of the precipitation received last year (1169.4 mm).

The IMD data showed that north-east Delhi has rain deficit of 55 percent; west Delhi 48 percent; central Delhi 9 percent; New Delhi 21 percent; north Delhi 3 percent; north-west delhi 20 percent ; south Delhi 4 percent and south west 12 percent this monsoon season so far. Only East Delhi was an exceptional case which received 30 percent excess rainfall. Delhi stared at a much larger rain deficit till September 20. However, a late spell of incessant rains from September 21 to September 24 — due to an interaction between a cyclonic circulation and a low-pressure system — helped it cover the margin to a large extent.

The rainfall recorded at the Safdarjung Observatory swung from a 49% deficit on September 21 to a surplus of 39% on September 24. The capital recorded 164.5mm of precipitation against a normal of 125.1 mm in September.

Weather experts said that Delhi is an arid zone, which often sees less rain days. “Delhi is a dry area and the axis line of the monsoon trough is towards the south of its normal position. Hence, the city has received less rain,” experts said.

Though the country as a whole has received excess rainfall, the distribution has been uneven with the desert state of Rajasthan reporting 36 per cent more rains than normal and north-east region, which witnesses copious showers, receiving deficit rainfall.

IMD classifies rainfall in deficit when it is over minus 19%. If the rain falls between minus 19 and 19%, it is classified as normal but anything between 20 and 59% is considered ‘excess’ rainfall.