How should travellers handle Vietnam’s regional weather?
Plan Vietnam by region. March and April often work well across much of the country, but no month guarantees ideal weather everywhere. Northern winters can be cool and grey, central Vietnam is often wet later in the year, and the south has a tropical wet season with frequent afternoon rain.
Full answer
Vietnam does not have one weather season.
It is common for Hanoi to be cool, Hoi An to be wet and Ho Chi Minh City to be hot during the same trip.
Northern Vietnam
Hanoi and the northern lowlands usually have cooler winters and hot, humid summers.
December to February can be dry but grey and surprisingly cool, especially in unheated rooms. March and April are often pleasant before the summer heat becomes heavy. May to September is hotter and wetter, with storms and short periods of intense rain. October and November can also be very good.
Mountain areas such as Sapa and Ha Giang are colder than Hanoi. Fog can hide the views, winter nights can be cold and summer rain can affect roads. Rice terraces also change through the year, so check what the landscape will look like rather than relying only on temperature.
Central Vietnam
Hue, Da Nang and Hoi An often have their driest weather from roughly February to August, though heat becomes intense in the middle of the year.
The wetter period commonly arrives later than in the south. Heavy rain and flooding can affect central Vietnam from September into the end of the year, and tropical storms may disrupt transport and beach plans.
Do not assume that a dry forecast in Hanoi means Hoi An will be dry too.
Southern Vietnam
Ho Chi Minh City and the Mekong are warm throughout the year.
The drier months are generally from December to April. The wet season usually runs from around May to November. Rain often comes in heavy afternoon bursts rather than lasting all day, although flooding and prolonged storms do occur.
The wet season can still be a good time to visit. The countryside is green, crowds may be lower and many days contain long dry periods. Carry rain protection and leave room around boat trips and flights.
Ha Long Bay and the coast
Mist can make Ha Long Bay atmospheric, but it can also hide the limestone landscape. Storms may lead to cruise changes or cancellations, particularly in the hotter, wetter months.
Beach weather also differs by region. Central beaches and southern islands do not share the same calendar. Check the exact coast and month before adding a beach stay.
How to plan a mixed trip
Look at each region separately, then decide which weather compromises you can accept.
A March or April trip often combines manageable conditions in the north, centre and south. An October trip may be pleasant in Hanoi but wet in central Vietnam. A January trip can be warm in the south and cool in the north.
Use climate patterns for planning, then check current forecasts and official warnings close to departure. Weather in Vietnam is variable enough that a perfect national window should never be promised.