The September rainfall in India is 27% more than what’s normal for the month. With a fresh rain-bearing pressure system forming in the Bay of Bengal, it is also likely that the withdrawal of the monsoon, which normally starts by September 17, is expected to be delayed.

Until August-end, a crippling rainfall deficit had brought India dangerously close to a drought like situation with a nearly 9% deficit, but a resurgence of rainfall since September has narrowed the deficit to 3%.

‘Not unusual’

Delayed monsoon withdrawals aren’t unusual. In 2019, the southwest monsoon commenced withdrawal on October 9, and last year, the withdrawal began on September 28. The monsoon also saw delayed withdrawals in 2017 and 2018.

From September 1-20, rainfall was excessive in all regions of the country. Central India saw an excess of 71% over what’s normal and northwest India 26% over its normal.

The monsoon completely withdraws from India around mid-October.

There are no signs of monsoon withdrawal from North India for the next 10 days, IMD Director General Mrutunjay Mohapatra said in a statement on September 16.

According to the India Meteorological Department (IMD), the monsoon withdrawal from northwest India takes place if there is cessation of rainfall activity over the area for continuous five days.

An anti-cyclonic wind has to form over the lower troposphere, and there should also be considerable reduction in moisture content.