Hai Phong has a real sea season, a real typhoon season and a run of clammy late-winter weeks that catch people out. Here is how the year runs, month by month, and which weeks suit a boat trip rather than a food trip.
Hai Phong sits on the northern coast about 100km (60 miles) east of Hanoi, and for most foreign travelers it is the mainland stop on the way to Cat Ba Island rather than a destination in its own right. That makes the best time to visit Hai Phong a question with two answers, because the conditions that suit a boat trip into Lan Ha Bay are not the ones that suit two days of eating your way around a port city. The north has four genuine seasons here, a real typhoon window, and a run of damp late-winter weeks that nobody warns you about.
The short answer on the best time to visit Hai Phong
If you are coming for the coast and the islands, aim for May to early July, when the water is warm and the sea is usually calm. If you are coming for the city itself, its French-era streets and its street food, take September to November instead, when the air is dry and cool and you can walk all day without wilting. Both answers avoid the same thing: the late-summer storm window, when boats to Cat Ba can stop running for days.
May to early July: the sea season
This is the window if the islands are the point of the trip. The water is warm, the sea is usually flat, and the sun is strong enough to turn the surface of Lan Ha Bay properly green without the storm risk that arrives later in the summer. The trade-off is company. These are the Vietnamese school holidays, island rooms are at their most expensive, and the ferry queues on a weekend are long. The first half of June tends to be the best balance between weather and crowds.
May: the flame tree weeks
Hai Phong is known in Vietnamese as the city of red flamboyant flowers, and in May that is literal rather than poetic. Flame trees bloom along the central streets, around the flower gardens and the edge of Tam Bac Lake, and the city usually holds a flame flower festival during the month. If you want the city looking its best and do not need a beach, this is the week of the year to choose.
July to September: storm season on the Gulf of Tonkin
- This is the peak of the typhoon season in the Gulf of Tonkin, and boats to Cat Ba can be suspended for several days at a time
- Room rates stay high because it overlaps the domestic summer holidays, so you pay the most in the riskiest weeks of the year
- If you go anyway, book only rooms with free cancellation and leave a spare day in the plan for the crossing
- September brings the Do Son buffalo fighting festival, held on the ninth day of the eighth lunar month, which usually falls in September
September to November: the most comfortable months
Once the storms clear, the weather turns dry, the sun softens and a cool breeze comes off the water. The sea is still warm enough to swim in through early autumn, and the city becomes ideal for walking, which is how you want to eat here. Island room rates drop noticeably and the ferry terminal stops being a bottleneck. For anyone here for the food and the architecture rather than a beach, this is the season.
December to April: cold air, hot food, empty temples
Winter here is genuinely cold by the standards most visitors expect of Vietnam, with wind coming straight off the sea. Swimming is out, but this is the season for slow travel: sui din (glutinous rice balls with a black sesame filling in hot ginger syrup), field crab hotpot, the Bach Dang Giang memorial site north of the city, and the old temples in the center. The weeks after Tet, the lunar new year, are festival season, especially at Con Son and Kiep Bac in Hai Phong city (formerly Hai Duong province).
February and March: the damp weeks
These two months bring drizzle and a northern phenomenon locals call nom, where warm moist air meets cold surfaces and everything sweats: floors, walls, hotel corridors, the clothes in your bag. It is not dangerous, just relentlessly clammy, and the sky stays a flat gray for days at a time. The sea is cold. If these are your only possible dates, consider putting Hai Phong late in your Vietnam trip and heading south first.
Do not pick your summer dates from your own calendar. Pick them from the marine forecast, two or three days out. Shifting a trip by 48 hours is the difference between a clear morning kayaking in Lan Ha Bay and two days watching rain from a room you have already paid for, because the boats stop running long before the storm actually arrives.
Festivals worth timing a trip around
- The flame flower festival in May, when the city center is at its most photogenic
- The Do Son buffalo fighting festival on the ninth day of the eighth lunar month, usually September
- The spring festivals at Con Son and Kiep Bac in the first lunar month, a few weeks after Tet
- Avoid the national holidays around April 30 and September 2 unless you like crowds, because island room rates spike hard
What to know before you fix a date
- Travel midweek rather than at a weekend. In summer the difference in crowds and island room prices is large
- If a storm is forecast, cancel the island leg first and keep the city days, which run normally in bad weather
- Pack a warm layer for winter, because the wind at Do Son and on Cat Ba is much sharper than in the city streets
- In the damp months, ask for a room on a higher floor with air conditioning that also heats
- Sea swimming is realistic from roughly May to September, and still pleasant into early October in a warm year
