Hoi An Heritage Walk Blog

If you search for Hoi An in October, you will find two kinds of photograph. One shows lanterns reflected in a calm river. The other shows the same street with the river in it: water up to the shop counters, a sampan being rowed past a tailor’s, a man on a motorbike pushing a bow wave. Both are real, and often they were taken a few days apart.

Flood season puts a lot of travellers off Hoi An altogether, and some of them are right to stay away. But a flood here is not a freak event. It is part of the town’s yearly routine, and the town has four hundred years of practice at it. This guide explains what really happens, what it means for a visit, and how to plan a trip between September and December that you will not regret.

The short version

• The rainy season in central Vietnam runs from about September to December. October and November are the wettest months and the ones most likely to bring floods to the Ancient Town.
• Most rainy-season days are not flood days. Expect grey skies, heavy showers and some dry spells. A flood that reaches the streets usually comes in a short burst after several days of very heavy rain, often linked to a tropical storm or typhoon further up the coast.
• A typical flood lasts from a day to a few days in the lowest streets. The water rises, sits, drains, and the town cleans up quickly.
• The streets nearest the river flood first. If you sleep a few blocks inland or on higher ground, a flood is usually an inconvenience rather than a crisis.
• Build in slack. Two buffer days, flexible bookings and travel insurance turn a flood from a ruined trip into a story.

Why Hoi An floods

Hoi An sits near the mouth of the Thu Bon, one of the largest river systems in central Vietnam. The Thu Bon and its neighbour, the Vu Gia, drain a big area of steep mountains to the west. When monsoon rain and tropical storms hit those mountains in autumn, all of that water comes down to a flat coastal plain within a day or two. The Ancient Town is only a few metres above the river at its lowest points, so when the river rises, it spreads into the streets.

The thing that made Hoi An a great port made it a flood town too. Merchants built right on the waterfront because the river was their road. Their warehouses opened onto the water so cargo could be unloaded straight from the boats. A building that is easy to load from a boat is also a building the river can walk into. Our Thu Bon River guide tells the trading side of that story. This is the other side.

There is a modern factor too. Over the past twenty years several hydropower dams have been built upstream in the Vu Gia–Thu Bon basin. In some bad years, residents and local media have blamed sudden water releases during storms for making floods downstream worse. Others argue that the dams also hold water back. It is still a live debate in Quang Nam. For a visitor the practical point is simple: floods can rise faster than you might expect, so take official warnings seriously.

What a flood day actually looks like

It usually starts with rain that does not stop. Two or three days of heavy, steady downpours, a weather warning on local TV, and the river turning a thick brown, flowing faster each hour. Shopkeepers along the waterfront start moving stock onto upper shelves and then upstairs. Restaurants stack their chairs on the tables. By the time water appears in the street, most of the town has already done its preparation, because most families have done it every year of their lives.

The water reaches the riverside streets first. Bach Dang Street, which runs along the bank, goes first. Then the river pushes up the side lanes into Nguyen Thai Hoc Street. In a bigger flood it reaches Tran Phu Street, and the lower ends of the streets running north from the river. Streets further inland may stay dry even when the waterfront is under a metre of water. The island of An Hoi, across the An Hoi Bridge, is low and floods early.

What follows looks strange but is not chaotic. Boats work as taxis in streets that were dry the day before. People in rain ponchos wade to check on their shops. Some cafés on higher ground stay open, and their owners watch the water from the doorway. The lanterns stay up. Then the river drops, often as quickly as it rose, and leaves a layer of mud. Within a day or so people are hosing out shopfronts, and soon after the street is selling silk again.

Not every flood is so mild. Central Vietnam has had some catastrophic years. People in Quang Nam still talk about the great flood of 1964. In October and November 2020 a string of storms brought some of the worst flooding and landslides the region had seen in decades. Typhoon Damrey in November 2017 also left the Ancient Town deep under water, just days before world leaders arrived in nearby Da Nang for the APEC summit. A routine flood and a disaster are different events. Pay attention to which one is forecast.

How the old houses were built for it

Once you know about the floods, the architecture of the Ancient Town starts to make sense in a new way. The best place to see this is in the merchant houses.

At Tan Ky Old House on Nguyen Thai Hoc Street, look for the flood marks on the wall near the back: horizontal lines with dates beside them. In the worst years the water in that room rose well above head height. The family did not leave. They moved their goods upstairs, waited, and cleaned up afterwards, generation after generation.

At Phung Hung Old House, near the bridge, the answer is built into the floor. A square trapdoor in the upper storey sits directly above the ground-floor room. When the river rose, furniture and stock went straight up through it. In serious floods the upper floor also became a shelter for neighbours. The house rests on heavy ironwood columns on stone bases. Ironwood survives repeated soaking in a way that cheaper timber does not.

Even the Japanese Covered Bridge has a flood story. The small shrine at its centre is dedicated to Bac De Tran Vo, a Taoist guardian invoked against floods and natural disasters. Centuries of high water and typhoons are part of why the bridge needed its major restoration in the early 2020s. Our guide to the Japanese Bridge covers that story.

None of this is decoration. It is a building tradition designed around a disaster that comes back every year. Seeing it in the town’s wettest months, perhaps with mud still drying on the step, is one of the more honest ways to understand the place. Our guide to the merchant houses and the heritage ticket explains how to visit them.

Should you go in October or November?

It depends on what kind of trip you want.

Think twice if you have only one or two days in Hoi An and your whole trip depends on them. Think twice too if you are set on beach days, if you are travelling with very young children or anyone with limited mobility, or if your trip cannot move by a day. A badly timed storm can close sites, cancel boat trips and the lantern-release boats, and make the road to My Son or the Hai Van Pass unsafe for a while.

It can be a good time if you are flexible, have three or more days, and care more about the town than the beach. Crowds are thinner than in the dry season and rooms are often cheaper. Many rainy days give you mornings or afternoons dry enough to walk. And you see Hoi An as a working river town rather than a backdrop for photos.

If you can choose, September and December are a reasonable compromise. They are still rainy, but floods are less frequent than at the October–November peak. For the most comfortable weather, the dry months from about February to May are still the safest bet, as our Hoi An travel guide explains.

How to plan a rainy-season trip that works

• Where you sleep matters most. Ask any hotel or homestay directly: “Did this building flood last year?” Places on An Hoi island, on Bach Dang Street or right on the waterfront are lovely in dry weather and the first to be cut off in a flood. A guesthouse a few blocks north of the river, or in the Cam Pho area to the west, is usually a safer choice. Beach areas such as An Bang and Cua Dai do not flood like the old town, but they get the full force of storms, and the coast there has suffered serious erosion.
• Keep two buffer days. Plan the things you cannot miss, such as the heritage ticket sites, a tailor fitting or a cooking class, for the first half of your stay, so a flood near the end only costs you extras.
• Book flexibly and get insurance. Choose refundable rooms where you can. Check that your travel insurance covers weather delays. Flights into Da Nang usually keep operating, but typhoons do cause delays and cancellations.
• Watch the forecast, not just the rain. A wet day is normal. What you want to know is whether a tropical storm or typhoon is forecast to make landfall in central Vietnam, and whether heavy rain is expected in the mountains upstream. Vietnam’s National Center for Hydro-Meteorological Forecasting publishes official warnings. Your hotel staff will usually know a day ahead whether the river is expected to rise.
• Pack for it. A proper rain jacket or a cheap poncho from any corner shop, sandals that can get wet, a dry bag for your phone, and a power bank in case there is a blackout.
• Expect closures without suspicion. Ticketed houses near the river, boat trips, the basket-boat tours at Cam Thanh and the full-moon lantern release can all close at short notice when the water is high. That is normal, not a scam. My Son Sanctuary can also close after heavy rain. Check the day before.

Staying safe if the water comes up

• Do not wade through floodwater for fun. It hides open drains, broken paving and debris, it can carry sewage, and in deeper water there may be a current. Downed or flooded electrical lines are a real risk.
• Do not ride a motorbike through flooded streets. Engines stall, potholes vanish, and every year people are swept off roads in central Vietnam’s floods.
• Follow local instructions. If police, ward officials or your hosts tell you to move to higher ground or stay inside, do it. They have done this many times before.
• Keep your phone charged and your passport dry and high up. Tell someone at home where you are staying.
• Stay away from the river itself during a flood, including the waterfront edge and the bridges if the water is near them.

A flood-season day in Hoi An

If you wake up to rain but no flood, here is a route that keeps you mostly under a roof and shows you the town’s relationship with its river.

1. Morning: start with breakfast near the Central Market. The market runs whatever the weather, and you can watch the river level from the edge of it.
2. Mid-morning: use your heritage ticket on Tan Ky and Phung Hung. Look for the flood marks and the trapdoor, and ask the family members who often sit inside about the worst year they remember.
3. Late morning: the Museum of Trade Ceramics is a dry, quiet hour that explains what all those boats were carrying.
4. Afternoon: head inland to the Fujian Assembly Hall, dedicated to Thien Hau, protector of sailors. Our assembly halls guide covers it and the others nearby. In a town shaped by water, the sea goddess makes sense.
5. Evening: if the waterfront is dry, walk it at dusk. If it is not, watch from a café on higher ground and come back to the lanterns tomorrow.

Hoi An survived as a port for four centuries by living with its river, not by fighting it. Seeing the town in the season when that relationship is most visible is not second best. It is just a different trip. Plan it with some slack, sleep away from the lowest streets, and take the warnings seriously, and you may find you understand the place better than the visitors who only came for the dry-season photographs.