The Monsoon's September Slowdown
After an active period, the southwest monsoon has entered what meteorologists call a “break” or “weak” phase. This is characterized by a significant reduction in rainfall, particularly over peninsular and central India. According to the India Meteorological
Department (IMD), this subdued activity is expected to continue for several days, especially in the southern peninsula. This doesn't mean the monsoon is over; rather, its driving engine is pausing. The primary cause is the shifting of the monsoon trough—an elongated low-pressure area that is a key driver of rainfall—towards the foothills of the Himalayas. This shift pulls moisture away from the plains, leading to drier conditions in many parts of the country while often increasing rain in the northeastern states and Himalayan foothills.
All Eyes on the Bay of Bengal
In this quiet phase, the Bay of Bengal becomes the centre of attention. This body of water is the birthplace of low-pressure systems and cyclonic circulations that act as boosters for the monsoon. The IMD is currently monitoring the potential formation of a fresh cyclonic circulation over the central and adjoining northwest Bay of Bengal. Forecasters anticipate that this circulation will lead to the development of a low-pressure area over the same region around September 11. Such systems are crucial because they have the power to pull the monsoon trough southward, away from the Himalayas and back over the Indian plains. This re-energizes the monsoon, leading to a new spell of widespread rainfall.
What Forecasters Are Watching For
The key question now is how this potential low-pressure system will develop. Its strength, location, and subsequent movement will determine the fate of rainfall for the next phase of the season. According to the IMD, a cyclonic circulation is already present over East Uttar Pradesh and adjoining Bihar, which is maintaining some rainfall in northern and central India. However, the new system forming in the Bay is the one that holds the potential for a more widespread revival. Forecast models suggest it will likely form over the west-central and northwest Bay of Bengal, near the coasts of north Andhra Pradesh and south Odisha. Its intensification could bring increased rainfall to eastern and adjoining parts of Peninsular India in the coming week.
The Impact on a Deficit Season
This next spell of rain is critically important. The 2026 monsoon season has been marked by erratic and uneven distribution, with the country facing a rainfall deficit. A weak start to the season had already raised concerns for the Kharif sowing period. While the overall sowing gap has narrowed, key crops like rice, maize, and cotton are still lagging behind last year's levels in several states. A prolonged dry spell in September could place these standing crops under significant stress, impacting yields and potentially pushing up food prices. The September rains are also vital for replenishing soil moisture ahead of the winter (Rabi) cropping season and for filling up reservoirs that are crucial for irrigation and drinking water supplies through the dry months.
Is the Monsoon Withdrawing?
It is important to distinguish between a weak phase and a formal withdrawal. The IMD has a specific set of criteria for declaring the monsoon's withdrawal, which includes five consecutive days of no significant rainfall and a change in atmospheric wind patterns. Currently, those conditions have not been met. While rainfall has reduced over the peninsula, it remains active over other parts of the country, such as north and central India. Therefore, this is simply a lull, not an end. The upcoming activity in the Bay of Bengal will dictate whether the country sees another comprehensive spell of rain before the withdrawal process officially begins, a process that itself can be erratic and take several weeks to complete across the country.
