Heavy rain, squally winds likely in West Bengal from September 22
The India Meteorological Department said heavy rainfall with gusty winds is likely across parts of West Bengal from September 22 to 26 due to a deep depression forming over the Bay of Bengal. A low-pressure area over the east-central Bay may intensify into a depression on September 21. Winds of 40-50 kmph are expected in Purba Medinipur and South 24 Parganas, and 30-40 kmph thunderstorms in south Bengal including Kolkata. Darjeeling, Kalimpong, Jalpaiguri, Alipurduar and Cooch Behar face heavy rain from September 23 to 25. Fishermen were advised against venturing into the deep sea.
Source
The Hindu — National · read the original report ↗
Desk check · compared with the source
What the desk checked (5)
- A low-pressure area over east-central Bay of Bengal and adjoining north Andaman Sea is likely to intensify into a depression on September 21, 2026. — Attributed to IMD in the source; forecast, not confirmed event.
- Heavy rain and squally weather likely in West Bengal from September 22 to 26, with gusty winds of 40-50 kmph in Purba Medinipur and South 24 Parganas. — Figures and districts appear as stated in the source, attributed to IMD.
- Heavy rainfall in Darjeeling, Kalimpong, Jalpaiguri, Alipurduar and Cooch Behar from September 23 to 25. — Attributed to IMD; internally consistent with the rest of the forecast.
- The system is very likely to reach the west-central and adjoining northwest Bay of Bengal near north Andhra Pradesh-south Odisha coasts around the morning of September 23. — Direct quote from IMD statement in the source.
- Fishermen advised not to venture into the deep sea off the West Bengal coast from September 21 and during September 22-25, and to return by the night of September 21. — Advisory attributed to IMD; dates as given in source.
Analysts’ view opinion
This is a weather bulletin, but in West Bengal its political after-effects are rarely neutral. The districts named — coastal Purba Medinipur and South 24 Parganas, and the sub-Himalayan belt of Jalpaiguri, Alipurduar and Cooch Behar — sit among the state's most electorally contested terrain, and how relief is handled there tends to register directly with voters. The scale of damage is not yet known, but an administration that is seen to have prepared early can limit political cost; one seen to have been caught out cannot.
- Because the IMD has issued advance notice, any visible gap in preparedness invites the sharpest line of attack — that a warning existed and was not acted on.
- The advisory against venturing into the deep sea hits coastal livelihoods directly, and demands for compensation and relief can quickly acquire a political edge.
- Between September 22 and 26, visible actions — review meetings, field visits, relief arrangements — will function as political messaging as much as administration.
- North Bengal and the southern coastal belt have distinct political dynamics, so allegations of uneven or partisan distribution of relief are a familiar risk.
- With the system tracking towards the north Andhra–south Odisha coasts, Centre–State coordination and the question of central assistance could also enter the argument.
What to watch — Watch the post-rain phase: damage assessments, compensation announcements, and whether relief funding becomes a Centre–State point of contention.
The story is purely a meteorological forecast and establishes nothing about actual damage, government response, or any political reaction so far.
Deep dive
Research brief · 8 facts · 7 dates · exam-readyThe brief
Context
The India Meteorological Department (IMD) has warned that a low-pressure area over the east-central Bay of Bengal and the adjoining north Andaman Sea is likely to intensify into a depression on September 21, 2026, and deepen further. The system is expected to bring heavy rainfall and squally weather to parts of West Bengal from September 22 to 26, 2026. It is moving west-northwestwards towards the north Andhra Pradesh–south Odisha coasts. Such late-September systems form during the withdrawal phase of the southwest monsoon, when the Bay of Bengal is a frequent source of depressions affecting the eastern coast.
Key facts
- IMD says heavy rainfall with gusty winds is likely over parts of West Bengal from September 22 to 26, 2026, due to a deep depression forming over the Bay of Bengal.
- A low-pressure area over the east-central Bay of Bengal and adjoining north Andaman Sea is likely to intensify into a depression on Monday, September 21, 2026.
- Rainfall intensity is expected to be higher in the coastal districts of Purba Medinipur and South 24 Parganas, with gusty winds of 40-50 kmph.
- Thunderstorms with lightning and winds of 30-40 kmph are likely at one or two places in the remaining south Bengal districts, including Kolkata, till September 25.
- Heavy rainfall is forecast in the sub-Himalayan districts of Darjeeling, Kalimpong, Jalpaiguri, Alipurduar and Cooch Behar from September 23 to 25.
- Thunderstorms with gusty winds are likely over Uttar Dinajpur, Dakshin Dinajpur and Malda in north Bengal during the period.
- The system is very likely to reach the west-central and adjoining northwest Bay of Bengal near the north Andhra Pradesh–south Odisha coasts around the morning of September 23.
- Swell waves of 16.0-19.0 second period and 0.9-1.1 m height were forecast up to 20:30 hours on September 21, 2026, with a possibility of surging waves.
Timeline
- September 21, 2026Low-pressure area over east-central Bay of Bengal and adjoining north Andaman Sea likely to intensify into a depression; fishermen advised not to venture into the deep sea along and off the West Bengal coast and to return to the coast by night.
- Up to 20:30 hours, September 21, 2026Swell waves of 16.0-19.0 sec period and 0.9-1.1 m height forecast; possibility of surging waves.
- September 22, 2026Heavy rainfall with gusty winds begins over parts of West Bengal; fishing advisory in force from this date.
- Morning of September 23, 2026System very likely to reach west-central and adjoining northwest Bay of Bengal near the north Andhra Pradesh–south Odisha coasts.
- September 23 to 25, 2026Heavy rainfall in sub-Himalayan districts of Darjeeling, Kalimpong, Jalpaiguri, Alipurduar and Cooch Behar.
- Till September 25, 2026Thunderstorms with lightning and 30-40 kmph winds likely in remaining south Bengal districts, including Kolkata; fishing advisory valid to this date.
- September 26, 2026End of the forecast spell of heavy rain and squally weather over West Bengal.
Who has a stake
- India Meteorological Department (IMD) — Issues the forecast, warnings on wind speeds and swell waves, and the fishing advisory for the West Bengal coast.
- Fishermen along and off the West Bengal coast — Advised not to venture into the deep sea from September 21 and from September 22 to 25, and to return to the coast by the night of September 21; loss of fishing days.
- Residents of Purba Medinipur and South 24 Parganas — Face the highest rainfall intensity and gusty winds of 40-50 kmph.
- Kolkata and other south Bengal districts — Thunderstorms with lightning and 30-40 kmph winds at one or two places till September 25.
- Sub-Himalayan districts (Darjeeling, Kalimpong, Jalpaiguri, Alipurduar, Cooch Behar) — Heavy rainfall forecast from September 23 to 25.
- North Andhra Pradesh and south Odisha coasts — The system is likely to approach these coasts around the morning of September 23.
- Boat operators and coastal recreation users — Warned of surging waves; advised to ply with utmost vigilance and exercise due care.
Why it matters
Late-monsoon Bay of Bengal depressions can trigger heavy rain, lightning and squally winds across densely populated coastal and deltaic Bengal, disrupting livelihoods and marine activity. Advance IMD warnings on wind speed, swell waves and fishing bans are the primary tool to reduce loss of life at sea and enable district-level preparedness. The system's westward track towards the north Andhra Pradesh–south Odisha coasts means the impact extends beyond West Bengal.
UPSC angle
Prelims pointers
- A low-pressure area over the east-central Bay of Bengal and adjoining north Andaman Sea was expected to intensify into a depression on September 21, 2026.
- IMD forecast gusty winds of 40-50 kmph in Purba Medinipur and South 24 Parganas; 30-40 kmph thunderstorm winds elsewhere in south Bengal, including Kolkata.
- Sub-Himalayan West Bengal districts named for heavy rain: Darjeeling, Kalimpong, Jalpaiguri, Alipurduar, Cooch Behar (September 23-25, 2026).
- Other north Bengal districts flagged for thunderstorms: Uttar Dinajpur, Dakshin Dinajpur and Malda.
- The system was to move west-northwestwards towards north Andhra Pradesh–south Odisha coasts by the morning of September 23, 2026.
- Swell wave forecast: 16.0-19.0 second period, 0.9-1.1 m height, valid up to 20:30 hours on September 21, 2026.
Mains framing
A Bay of Bengal low-pressure area intensifying into a depression, and then a deep depression, illustrates how the eastern seaboard remains exposed to cyclogenesis during the withdrawal phase of the southwest monsoon. In this case the IMD forecast higher rainfall intensity over coastal Purba Medinipur and South 24 Parganas with 40-50 kmph gusty winds, thunderstorms with lightning over Kolkata and the rest of south Bengal, and heavy rain over the sub-Himalayan districts of Darjeeling, Kalimpong, Jalpaiguri, Alipurduar and Cooch Behar — a combination that simultaneously threatens deltaic coastal settlements, an urban metropolis with drainage constraints, and hill districts prone to rain-triggered instability. The system's west-northwestward movement towards the north Andhra Pradesh–south Odisha coasts underlines that such depressions are multi-State events requiring coordinated response. The immediate risk management levers visible in the source are precautionary: a fishing advisory barring deep-sea venturing from September 21 with a directive to return to the coast by that night, and warnings on swell waves of 0.9-1.1 m height with 16-19 second periods and possible surging waves, alongside cautions for boats and coastal recreation. The way forward lies in acting on such lead-time warnings — timely dissemination to fishing communities, lightning-safety messaging in south Bengal, and preparedness in hill and coastal districts.
Key terms
- Low-pressure area
- An area of relatively lower atmospheric pressure over the sea or land; in this case over the east-central Bay of Bengal and adjoining north Andaman Sea.
- Depression / deep depression
- Successively more intense stages of a low-pressure system over the sea, as classified by the IMD; the Bay system was expected to become a depression on September 21, 2026.
- Squally weather
- Weather marked by sudden, strong gusty winds, here forecast at 40-50 kmph in coastal Bengal and 30-40 kmph elsewhere in south Bengal.
- Swell waves
- Long-period waves generated by distant winds; forecast at 16.0-19.0 second period and 0.9-1.1 m height off the coast up to 20:30 hours on September 21, 2026.
- India Meteorological Department (IMD)
- The national weather agency that issued the rainfall, wind, swell wave and fishermen advisories in this story.
- Sub-Himalayan West Bengal
- Northern districts of the State at the Himalayan foothills — Darjeeling, Kalimpong, Jalpaiguri, Alipurduar and Cooch Behar — forecast heavy rain on September 23-25, 2026.
Practice questions
- Discuss how Bay of Bengal low-pressure systems during the late monsoon affect coastal, urban and sub-Himalayan districts differently, using the September 2026 West Bengal forecast as an illustration.
- Evaluate the role of IMD advisories — including fishing bans and swell wave warnings — in reducing disaster risk for coastal communities.
- Why is the Bay of Bengal more prone to depressions and cyclonic systems than the Arabian Sea, and what does the west-northwestward track of such systems imply for multi-State disaster coordination?
Grounded only in the source report — figures and dates are the source's, not inferred.