South Bengal rain forecast: Thunderstorms, gusty winds for 5 days from Thursday
Synopsis
After days of above-normal heat, south Bengal is bracing for a five-day wet spell starting Thursday as a strengthening cyclonic circulation over the Bay of Bengal drives thunderstorms across eight districts. Kolkata, sitting two degrees above normal temperature on Wednesday, is in the thick of the warning zone.
Key Takeaways
The IMD has forecast thunderstorms and light to moderate rain across south Bengal for the next five days starting Thursday, 18 September 2026 .
A yellow warning has been issued for eight districts : Bankura, Purulia, Jhargram, East Midnapore, West Midnapore, Howrah, North 24 Parganas, and South 24 Parganas.
A cyclonic circulation over the northwest Bay of Bengal is expected to strengthen and influence the West Bengal and Odisha coasts.
Gusty winds of 30–40 km per hour are expected; rainfall intensity is likely to ease from Monday .
North Bengal faces a separate heavy rain warning for Darjeeling, Kalimpong, Cooch Behar, Jalpaiguri , and Alipurduar , with activity expected to decrease from Friday .
Kolkata recorded 34.08°C on Wednesday, two degrees above normal; relief is expected as rain arrives from Thursday afternoon.
Weather conditions in south Bengal are set for a significant shift starting Thursday, 18 September 2026, as the India Meteorological Department (IMD) has forecast thunderstorms with light to moderate rain across the region for the next five days, ending a prolonged spell of oppressive heat. Kolkata, which recorded a maximum temperature of 34.08 degrees Celsius on Wednesday — two degrees above normal — is also expected to receive rain and thundershowers.
What Is Driving the Change
According to IMD officials, the monsoon axis currently extends from a low-pressure area over Rajasthan to the northwest Bay of Bengal, passing through Ranchi and Digha. A cyclonic circulation is additionally present over the northwest Bay of Bengal and is expected to gradually strengthen, directly influencing the West Bengal and Odisha coasts. Together, these systems are responsible for the anticipated multi-day wet spell.
Yellow Warning for Eight Districts
The IMD has issued a yellow warning for rain and thunderstorms across eight districts in south Bengal, covering both coastal and western zones. The districts under alert are Bankura, Purulia, Jhargram, East Midnapore, West Midnapore, Howrah, North 24 Parganas, and South 24 Parganas. Gusty winds reaching 30 to 40 km per hour are expected alongside the rainfall. The intensity of rain is, however, likely to decrease from Monday.
North Bengal Alert and Kolkata Outlook
Rainfall is also expected to increase in north Bengal on Thursday, with a separate yellow warning for heavy rain issued for Darjeeling, Kalimpong, Cooch Behar, Jalpaiguri, and Alipurduar districts. Light to moderate rain with thunderstorms and gusty winds of 30 to 40 km per hour are forecast across north Bengal, though activity there is expected to ease from Friday.
For Kolkata, cloudy skies are expected to build from Thursday afternoon, with rainfall probability rising through the day. Light to moderate rain with thundershowers is forecast to continue at least until Saturday. On Wednesday, the city's minimum temperature stood at 27.06 degrees Celsius, roughly one degree above normal, while relative humidity ranged between 52% and 97%.
Impact and What Comes Next
The incoming wet spell offers relief to residents who have endured above-normal temperatures over recent days. Notably, the strengthening cyclonic circulation over the Bay of Bengal adds an element of uncertainty to rainfall intensity — conditions that the IMD will continue to monitor. Citizens in low-lying coastal districts of south Bengal are advised to remain alert given the yellow warnings in place.
Point of View
But the strengthening cyclonic circulation over the Bay of Bengal deserves attention beyond the standard yellow warning framing. The combination of a monsoon-axis extension and an intensifying offshore system creates conditions where rainfall totals can exceed initial forecasts — particularly for coastal districts of East and West Midnapore, which have a history of flooding during similar synoptic setups. The IMD's qualifier that intensity decreases 'from Monday' implies at least three days of meaningful uncertainty. Authorities in low-lying areas should not wait for an upgrade from yellow before activating preparedness protocols.
NationPress
17 Sept 2026
Frequently Asked Questions
Which districts in south Bengal are under a yellow weather warning?
Eight districts are under a yellow warning for rain and thunderstorms: Bankura, Purulia, Jhargram, East Midnapore, West Midnapore, Howrah, North 24 Parganas, and South 24 Parganas. The warning covers both coastal and western areas of south Bengal.
Why is south Bengal expecting heavy rain now?
A cyclonic circulation over the northwest Bay of Bengal is strengthening and is expected to influence the West Bengal and Odisha coasts. Combined with a monsoon axis extending from Rajasthan through Ranchi and Digha, these systems are driving the multi-day rain forecast.
How long will the rain last in south Bengal?
The wet spell is forecast to last five days from Thursday, 18 September. Rainfall intensity is expected to start decreasing from Monday, according to the IMD.
What is the weather forecast for Kolkata this week?
Kolkata can expect cloudy skies from Thursday afternoon with increasing chances of rain through the day. Light to moderate rain with thundershowers is forecast to continue until at least Saturday, with gusty winds of 30 to 40 km per hour also likely.
Is north Bengal also affected by the rain warning?
Yes. A separate yellow warning for heavy rain has been issued for Darjeeling, Kalimpong, Cooch Behar, Jalpaiguri, and Alipurduar. However, rainfall activity in north Bengal is expected to ease from Friday — earlier than in the south.
