Shrayan Sen
After remaining stalled over Uttar Pradesh for nearly two weeks, the withdrawal of the southwest monsoon is finally poised to resume rapidly, paving the way for its retreat from West Bengal by this weekend. The transition, however, is proving dramatic — with dry winds tightening their grip over North Bengal while South Bengal sizzles under sudden afternoon thunderstorms.
According to the India Meteorological Department (IMD), the withdrawal line currently lies over eastern Uttar Pradesh, where it had been halted since late September due to successive low-pressure systems over the Bay of Bengal. These systems had kept moisture inflow active across eastern India, delaying the monsoon’s retreat.
Dry Northwesterlies Advancing
With weather systems now dissipating, dry northwesterly winds from North and Central India have begun advancing eastward. Meteorologists expect that once the withdrawal process restarts from Uttar Pradesh, it will progress swiftly through Bihar, Jharkhand, West Bengal, Odisha, and parts of the Northeast, possibly within a span of four to five days.
This rapid withdrawal usually occurs when the monsoon trough collapses, cutting off the Bay’s moisture feed and allowing dry continental air to dominate. The IMD’s withdrawal criteria — persistent dry weather, reversal of winds to northwesterly direction, and a marked drop in humidity — are likely to be fulfilled by the weekend.
North Bengal Turning Crisp and Dry
Even before official withdrawal is declared, Sub-Himalayan North Bengal is already drying rapidly. Cloud cover has thinned out, skies are clearer, and northwesterly winds are beginning to dominate, signalling the early onset of post-monsoon conditions.
Rainfall is now minimal, confined to very light or isolated showers along the foothills. Meteorologists expect North Bengal to meet withdrawal conditions by October 12–13.
South Bengal Caught in Clash of Winds
In contrast, South Bengal remains under the grip of wind convergence — where dry northwesterlies from the landmass collide with moisture-laden southeasterlies from the Bay. This clash is fuelling intense but short-lived thunderstorms over Kolkata, Howrah, Hooghly, Nadia, East and West Midnapore, North and South 24 Parganas.
These are classic withdrawal-phase thunderstorms, bringing lightning, gusty winds, and sharp evening rain bursts. The activity is likely to persist for another two to three days before drier air takes control.
Clearer Skies, Cooler Nights Ahead
By early next week, dry and pleasant weather is forecast to prevail across most of West Bengal. Clear skies and dropping humidity will mark the arrival of the post-monsoon period, with slightly cooler nights expected in North Bengal and the western districts.
Meteorologists believe the 2025 monsoon will withdraw completely from eastern India by mid-October. After weeks of stalled progress and lingering moisture, a swift and widespread retreat is now on the horizon — finally bringing Bengal’s long, humid monsoon to a close.