Southeast Asia is often imagined as a region of endless sunshine, tropical rainstorms, and sweltering heat. While this stereotype holds some truth, the reality is far more diverse. Most countries in Southeast Asia fall under a tropical climate, marked by high humidity and two dominant seasons: wet and dry.
But in some areas, particularly the highlands of Viet Nam, Myanmar, and Indonesia, subtropical conditions can bring unexpectedly cool weather — even snow.
Yes, you read that right. Snow in Southeast Asia. More on that later.
In this article, we break down the average temperatures, seasonal cycles, and climate challenges of each Southeast Asian country — from the steamy cities of Indonesia to the misty hills of northern Viet Nam.
The Tropics vs The Highlands: Southeast Asia’s Two Faces
Most Southeast Asian countries are located near the equator, giving them tropical rainforest or tropical monsoon climates. These regions experience little temperature variation year-round but alternate between a wet season and a dry season, each lasting about six months.
However, the northern regions of countries like Viet Nam, Laos, and Myanmar — as well as mountainous areas such as Papua, Indonesia — have subtropical or alpine climates with more noticeable seasonal shifts.
Let’s look at how temperature and climate vary across the region.
Indonesia: Hot and Humid All Year
- Average Temperature: 27°C to 30°C
- Seasons: Wet (November to March), Dry (April to October)
Indonesia’s climate is heavily influenced by the monsoon winds. During the wet season, heavy rains are common, especially in western and central regions. The dry season brings intense sun and occasional droughts, particularly in eastern islands like Timor or Sumba.
Climate Challenges: Flooding during rainy season, water scarcity and forest fires during dry months.
Fun Fact: In Papua’s Puncak Jaya, snow can still be found at elevations above 4,800 meters — Southeast Asia’s only remaining glacial area.
Malaysia and Singapore: Constant Heat, Sudden Storms
- Average Temperature: 26°C to 28°C
- Seasons: No true seasons, but wet periods occur during Northeast Monsoon (Nov–Mar) and Southwest Monsoon (May–Sep)
Both countries are located near the equator, with minimal temperature fluctuation. High humidity is the norm, and thunderstorms are frequent, especially in the afternoon.
Climate Challenges: Flash floods in urban areas, high heat index leading to heat stress.
Local Tip: Many locals carry umbrellas not just for rain but also for shade from the harsh sun.
Thailand: From Cool Breezes to Burning Heat
- Average Temperature: 22°C (cool season) to 35°C (hot season)
- Seasons: Cool (Nov–Feb), Hot (Mar–May), Rainy (Jun–Oct)
Thailand has a more pronounced seasonal cycle compared to equatorial countries. The hot season is notoriously scorching, especially in April. The cool season brings welcome relief, particularly in the north.
Climate Challenges: Heatwaves during the hot season, floods during monsoon months.
Fun Fact: Chiang Mai sees temperatures drop below 15°C in December — sweater weather by local standards.
Viet Nam: North vs South Divide
- North Viet Nam: 10°C to 30°C across four seasons
- South Viet Nam: 25°C to 35°C year-round
- Seasons (North): Spring (Mar–Apr), Summer (May–Aug), Autumn (Sep–Oct), Winter (Nov–Feb)
Viet Nam is the only country in Southeast Asia with four-season climate zones, but only in the north. Hanoi winters can be surprisingly chilly, with occasional frost in mountainous areas like Sapa.
Climate Challenges: Typhoons in the central coast, extreme heat in the Mekong Delta, winter cold snaps in the north.
Fun Fact: Snow occasionally falls in Sapa and Mount Fansipan, creating rare winter landscapes in a tropical country.
The Philippines: Islands and Storms
- Average Temperature: 25°C to 32°C
- Seasons: Dry (Dec–May), Wet (Jun–Nov)
The Philippines has a tropical maritime climate. The dry season is divided into cool dry (Dec–Feb) and hot dry (Mar–May). The rainy season overlaps with typhoon season, making some areas vulnerable to intense storms.
Climate Challenges: Floods, landslides, and typhoons — the country sees up to 20 typhoons annually.
Local Adaptation: Many coastal towns use elevated housing and rain-resilient infrastructure.
Myanmar, Laos, Cambodia: The Continental Tropics
- Average Temperature: 21°C (cool) to 38°C (hot)
- Seasons: Cool (Nov–Feb), Hot (Mar–May), Rainy (Jun–Oct)
These mainland countries have more continental traits — with greater seasonal variation, especially in highland areas. Laos and Myanmar can see temperatures below 10°C in winter months.
Climate Challenges: Crop failure due to heatwaves, poor irrigation during dry season, flash floods during monsoon.
Notable Case: In Shan State, Myanmar, frost can be observed in winter, affecting tea plantations.
Timor-Leste and Brunei Darussalam: Small Nations, Big Climate Swings
- Timor-Leste: Similar to eastern Indonesia, with pronounced dry season and temperatures around 30°C
- Brunei: Shares Borneo’s equatorial climate with Malaysia, humid and storm-prone
Climate Challenges: Timor-Leste faces drought-induced food insecurity; Brunei experiences frequent river overflows and flash floods.
Living with the Heat
Southeast Asia is a region where seasons are defined not by temperature but by rain, wind, and survival strategies. While most countries experience consistent warmth, the climate variation by altitude and latitude creates rich contrasts — from flood-prone cities to foggy highlands.
Understanding these seasonal patterns is key to building better cities, farming smarter, and staying safe in an era of climate change. It also calls for greater collaboration among ASEAN nations to strengthen resilience, share knowledge, and address the environmental challenges they all increasingly face.
Because in this part of the world, the weather doesn’t just change — it shapes life.
