Although Mother Nature doesn't always follow the rules, the weather in Southeast Asia is somewhat predictable. Most places in Southeast Asia experience two distinct seasons: wet and dry. Unless elevation is a factor, Southeast Asia is close enough to the Equator to stay warm throughout the year. Tropical or not, nights often feel cool after an afternoon of sightseeing in scorching temperatures.
Sunshine is ideal for any trip to Southeast Asia, but the rest of the world realizes that, too. Famous attractions and popular destinations are the most crowded during the dry-and-sunny months.
Traveling during the monsoon seasons is a mixed blessing. Although rain and mud may affect outdoor plans such as jungle trekking and scuba diving, you'll encounter fewer tourists and can negotiate better prices for accommodation.
Different Countries in Southeast Asia
The monsoon season in Thailand runs roughly between June and October. However, the rain can begin a month earlier or linger a month longer than expected. September is typically the wettest month in Thailand. Cooler places in the north, such as Chiang Mai and Pai, may be cloudy but often receive less rainfall than southern destinations. Rain begins a little earlier—around April—on the Andaman side of Thailand (e.g., Phuket and Koh Lanta) than it does in the east (e.g., Koh Tao and Koh Samui). Just as temperatures and humidity reach uncomfortable highs around late April, Thailand's wet season begins in May.
Your only escape from the heat right before monsoon season starts may be to get soaked at the Songkran festival in Chiang Mai!
Northern Laos experiences a tropical climate, while the southern part of the country is subequatorial. Unlike some other southeast Asian countries, Laos experiences wildly different weather across its various regions. The country experiences three seasons: cool and dry during continental monsoon season, dry and hot, and hot and humid.
Vietnam doesn't experience significant shifts in weather or temperature throughout the year, but the changes it does experience are distinct between the northern and southern parts of the country. Because of Vietnam's elongated shape, weather differs significantly between the north and the south. Temperatures in Hanoi can be quite cold. The southern part of Vietnam is in a tropical monsoon zone with November through April being relatively dry and the rainy season lasting from May through October.
Northern regions have hot and humid summer and cool and wet winters.
Indonesia is an excellent choice for a destination when Thailand, Laos, Cambodia, and other northern destinations are inundated with rain. The Indonesian archipelago is broad, and geological features can influence weather; however, you'll nearly always find someplace relatively dry to enjoy during the monsoon season. The dry season in Indonesia is roughly opposite that of Thailand; from June to September are the driest, coolest months to visit; July is one of the busiest months. Expect rain between November and April.
Like Indonesia, the Philippines is spread across a vast archipelago with many islands, volcanoes, and geological features that affect weather. Although farther east than much of Southeast Asia, the Philippines is still subject to the Southwest Monsoon. Expect heavy rains in the Philippines from June to September. Some island destinations are difficult to reach when the seas become rough. January, February, and March are the best months to visit Boracay. Typhoon season in the Philippines runs between May and October, with August being the worst month for cyclones.
Tiny Singapore is only 1.5 degrees north of the Equator, and weather remains reasonably consistent throughout the year. Showers can pop up at relatively any time to cool down the scorching afternoon average of 86 degrees Fahrenheit. Expect a little more rain in Singapore between November and January.
The Southwest Monsoon in Southeast Asia
The same weather system that delivers rain during India's monsoon season also affects Southeast Asia weather. Although timing can differ by a month or so based on where you are in Southeast Asia, the Southwest Monsoon typically begins around early June and finishes in late September. This pattern especially affects Thailand, causing the rainy season to typically fall between May and October.
Although no one appreciates rain on a big trip to Asia, the annual monsoons replenish fresh water, keep scenery green, and are crucial for the rice farmers. A minuscule delay of the arrival of the monsoon rains can cause crops to fail.
What to Pack: Regardless of when you visit Southeast Asia, you'll always want to pack light cotton clothing, sandals, and flip-flops. If you are visiting higher elevations or northern reaches of individual countries, a jacket might be necessary, but in general, climates are warm and humid year-round. Raingear is a good idea, but make sure it's breathable.
The Northeast Monsoon in Southeast Asia
Cold air from the Himalayas actually triggers the Northeast Monsoon that causes destinations in the southern part of Southeast Asia to experience rain while Thailand and neighboring countries are enjoying drier weather.
The best time to visit Bali, other places in Indonesia, and East Timor is usually between May and August when destinations farther north are becoming rainy.
What to Pack: Similar to the Southwest Monsoon, pack breathable gear that will dry quickly and will keep you cool.
Traveling During the Monsoon Season
Depending on your location and itinerary, visiting during the monsoon season can have little or significant impact on your plans. Blue skies can often be enjoyed throughout the day until an afternoon downpour sends everyone running for cover.
Unless a tropical storm in the region is wrecking havoc with weather systems, monsoon rains are usually more of a temporary annoyance than a showstopper.
Some tips for travel during the wet season:
- Always be prepared when traveling during the monsoon season; weather can change with little warning. Carry rain gear, make flexible travel plans, and consider purchasing a waterproof backpack to protect electronics.
- Wet conditions cause increases in the local mosquito population. Dengue fever, a mosquito-borne illness, is a real problem throughout Southeast Asia. Learn some ways to avoid mosquitoes while traveling.
- Build buffer days into your itinerary, particularly if you have a flight to catch. Heavy rain can affect road conditions and cause delays in public transportation.
- Unexpected downpours could make some outdoor activities such as trekking much more dangerous.