Coast & Islands
The cyclone season on the Bay of Bengal comes in two parts
Storms cluster before and after the monsoon rather than during it, and the difference between a warning and a landfall is where travel plans are actually decided.
By Leela Fernandes4 min read
Why the season has two peaks instead of one
Tropical cyclones need warm sea water, moisture and relatively little change of wind with height. In the north Indian Ocean the sea is warm enough for much of the year, but the middle of the summer monsoon brings strong winds aloft that tear developing systems apart before they can organise. The result is a season split in two.
The first part comes before the monsoon establishes itself, broadly in the pre-monsoon weeks of spring and early summer. The second and generally more active part comes after the monsoon withdraws, running through the late autumn and into early winter, when the sea is at its warmest after months of heating and the upper winds have relaxed.
This bimodal pattern is well documented and is the reason cyclone advisories are a feature of the Indian calendar twice a year rather than continuously. It also means the quiet spell in between is not evidence of a quiet year.
The Bay produces more of them than the Arabian Sea
Historically the Bay of Bengal has generated substantially more cyclonic systems than the Arabian Sea, and the ones that reach the east coast tend to matter more because of the shape of the coastline and the density of population behind it. A shallow bay with a funnelling coast pushes storm surge inland much more effectively than a steep-to shore does.
The Arabian Sea is not exempt and has produced significant storms affecting the west coast and Gujarat, and there is an active scientific discussion about whether activity there is changing. That discussion is not settled and this is not the place to resolve it, but it is a reason to treat the west coast as low-probability rather than no-probability during the season.
For a traveller the asymmetry is worth knowing simply for planning. A late-year trip to the east coast carries a small but real chance of running into a warning, and that chance is smaller on the opposite coast in the same weeks.
A warning changes travel before the storm arrives
The national meteorological service tracks developing systems and issues staged advisories as confidence about track and intensity increases, and state and district administrations act on them. Those actions are what a traveller actually encounters: fishing suspended, ports closed, schools shut, and in the more serious cases evacuations from low-lying coastal areas.
Transport responds in advance rather than at the last minute. Airlines cancel and rebook ahead of expected conditions, railways cancel or short-terminate services on affected routes, and long-distance buses stop running. This happens a day or two before landfall, which means a trip can be disrupted while the sky where you are standing is still clear.
The reasonable posture is not anxiety but attention. If you are travelling on either coast in the active months, look at the official forecast every morning, and know what your booking allows if a service is cancelled. Preemptive cancellation is a safety measure, not an inconvenience being visited on you.
The rain outlasts the wind
Public attention concentrates on landfall, but the longer-lived effect is usually the rain. A system that has come ashore weakens quickly and then drifts inland as a large area of very heavy rainfall, which can produce flooding hundreds of kilometres from where the wind did its damage, days after the storm stopped being a storm.
That is why disruption to rail and road often continues well after the coast has cleared up. Track can be underwater in one district while another has bright weather, and rerouted services take time to unwind. Recovery of a timetable after a major event is measured in days.
It also means the safe-looking option of moving inland is not automatically safe. Low ground near a river receiving that rain is a worse place to be than a well-built building on the coast after the wind has passed.
Travelling in the season without avoiding it
Most late-year trips to the east coast are entirely uneventful, and treating the whole season as off-limits would rule out some of the best weather of the year in Tamil Nadu and Odisha. The sensible approach is to accept a small probability of disruption and to make it survivable.
In practice that means flexible or refundable bookings where the cost of flexibility is modest, a day of slack before any fixed commitment, and accommodation that is not on a beach at the front of a low-lying spit. It also means taking local instructions seriously rather than making an independent assessment from a hotel window.
And it means keeping a sense of proportion. A warning covering a stretch of coast affects the whole of it, but the severe conditions are usually confined to a smaller area near the track. Following the official updates, rather than the more excitable secondhand versions, is the difference between adjusting a plan and abandoning one.
Common questions
Which months are riskiest on the east coast?
Broadly the post-monsoon stretch from around October into early December, with a secondary risk before the monsoon in spring. The exact distribution varies year to year, so the meteorological department’s current outlook is a better guide than any general rule.
Will a cyclone warning cancel my flight?
It may, and often a day or more in advance, because airlines and railways act on forecasts rather than waiting for conditions to deteriorate. Check the operator’s updates directly and be aware that rebooking capacity fills quickly once cancellations start.
Is the west coast safe during cyclone season?
Safer, in the sense that the Arabian Sea has historically produced fewer systems than the Bay. It is not immune, and significant storms have affected it, so the same habit of checking the forecast applies even though the odds are better.
Features writer, Traveology
Leela writes about states, hills, coast & islands, mostly the parts other people skip and is happiest when a piece answers the question completely.
