There is no right time to go to Southeast Asia. It is a large region with a climate affected by a variety of different but interrelated weather systems.
With the right ordering of a regional itinerary though, assuming you have enough time, you can chase the sun to an extent and minimise your wet days. That said, don’t assume that the monsoon turns wherever you’re going into a malarial swamp—it won’t (at least, most of the time). Sights like Angkor Wat can be magnificent after a tropical downpour. And monsoon rainfalls tend to be short and sharp rather than miserable, all-day drizzles.
There are of course, some places best avoided for particular reasons. Divers should skip Ko Tao in mid- to late-October when visibility is poor Hoi An reliably floods every late October to early November and a lot of eastern Indonesia’s tourism scene is on a go slow during the peak monsoon period between December and January, for example, but these situations are few and far between.
Generally speaking, with the exception of a few mountaintops in Indonesia, northern Vietnam and Burma, all of Southeast Asia is pretty warm, swinging between 25 and 35 degrees from cool to hot season throughout the year. Humidity is high, year round.
If you’ve never experienced debilitating humidity before, and we mean debilitating when we say debilitating, perhaps factor in a day or two of taking it easy upon arrival to ease the shock. There is no way to describe the cloying heat of Southeast Asia—you need to experience it to understand it.
In summary, weather should play a part in your holiday planning, but there is always somewhere worth heading at any time. A small shift in your travel dates can make a big difference, but don’t skip a destination solely because you’ve read it might be rainy.
Below are the primary periods when you’ll be likely to see a significant amount of rainfall (and perhaps flooding). Bear in mind that with the entire planet’s climate system getting a shake-up, weather patterns are not as plain and simple as they used to be even a decade ago. Please see our weather pages for each country for more details.
Indonesia: Regional variables are at play here, but broadly, Indonesia’s monsoon runs from October to April, sometimes May. Exceptions include Maluku and Papua where the wet is (roughly) June to October. More information here.
Malaysia: West coast Peninsular Malaysia sees its monsoon hit May to October. East coast Peninsular Malaysia gets drenched from November to March. Sabah and Sarawak see their heaviest rainfall between October and March, though they can see significant rain at any time through the year. More information here.
Singapore: Can see significant rain any time of the year. More information here.
Thailand: Northern Thailand has its monsoon May to November. The southwest has rainy season from late April to October, while the southeast sees rain from August or September to December. More information here.
Vietnam: Northern Vietnam’s wettest months are July and August, Central Vietnam is wet from August to November (Hoi An often floods in late October or early November). Southern Vietnam sees much of its rain between April and September. More information here.
Planning well is an integral part of getting the most out of your trip. Be it picking the right backpack, the right vaccinations or the right country, the simple decisions are often the most important.