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.
Obviously, 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 less tourists and can negotiate better prices for accommodation.
The Southwest Monsoon
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.
The Northeast Monsoon
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.
Traveling During the Monsoon Season
Depending on your location and itinerary, traveling during the monsoon season can have little or great 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.
Weather in Thailand, Laos, Vietnam, and Cambodia
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 begins may be to go get soaked at the Songkran festival in Chiang Mai!
The monsoon season in Thailand, Laos, and Cambodia 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.
Because of Vietnam's oblong shape, weather differs greatly between the north and the south. Temperatures in Hanoi can be quite cool.
Weather in Indonesia
Indonesia is a good choice for destination when Thailand, Laos, Cambodia, and other northern destinations are inundated with rain. The Indonesian archipelago is wide, 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.
Weather in the Philippines
Like Indonesia, the Philippines is spread across a large 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.
Weather in Singapore
Tiny Singapore is only 1.5 degrees north of the Equator, and weather remains fairly 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 the months of November and January.