Quick Answer
Thailand Weather & Seasons
Three seasons, two monsoons, and one simple rule: which coast suits your dates.
Understanding Thailand's weather requires understanding that the country has two separate coastlines — the Gulf of Thailand (east/south-east coast) and the Andaman Sea (west coast) — each affected by different monsoon systems. This means the 'rainy season' question can't be answered without knowing where you're going.
The broad strokes: Thailand has a cool season (November–February), hot season (March–May), and rainy season (June–October). But the Andaman Coast's rainy season runs May–October while the Gulf Coast has its main rains in October–November. A traveler who knows this can always find good weather somewhere in Thailand.
Cool Season (November–February)
The best all-around weather. Temperatures: 15–20°C at night in Chiang Mai, 22–28°C in Bangkok, 28–32°C in the south. Almost no rain in the north and center. Both coasts are at or near their best. It's peak tourist season — book accommodation and transport well in advance for December and January. Yi Peng Lantern Festival in Chiang Mai (November) and New Year celebrations nationwide are major draws. Humidity is lower than the rest of the year, making sightseeing genuinely comfortable.
Hot Season (March–May)
Thailand's most intense heat. Bangkok regularly hits 38–40°C in April. Chiang Mai temperatures and agricultural burning creates a smoky haze (March–April) that reduces visibility significantly. The beaches are still pleasant if you can handle the heat; most activity happens early morning or late afternoon. Songkran water festival (April 13–15) is a spectacular national celebration — the entire country has a water fight for three days. Fewer tourists mean lower prices and more authentic experiences.
Rainy Season (June–October)
Rain doesn't mean ruined. In Bangkok, Chiang Mai, and the northeast, rain falls mainly in afternoon/evening thunderstorms — mornings are typically clear. The Andaman Coast (Phuket, Krabi, Koh Lanta) gets the worst of it — rough seas and heavy rain can shut down ferries. The Gulf Coast (Koh Samui area) is in its dry window through to September, then gets its own rain from October–November. Prices drop 30–50%, crowds are minimal, and the landscape turns brilliant green.
Month-by-Month Guide
January: Peak season, clear everywhere, busy and expensive. February: Still great weather, crowds start to thin. March: Heat rising, Andaman still good, north gets smoky. April: Very hot everywhere, Songkran festival, Andaman monsoon starts. May: Hot, Gulf Coast still good, budget travelers' window. June–September: Low season Andaman, Gulf Coast fine, Bangkok hot and wet. October: Gulf Coast rains arrive, Andaman improving, chao phraya flooding possible. November: Cool season begins, Yi Peng festival, excellent everywhere. December: Peak season, Christmas and New Year, expensive and crowded.
Disclaimer
Frequently Asked Questions
Related Planning Guides
Get Thailand Travel Updates
Monthly updates on visa changes, new destination guides, best-value hotels, and seasonal travel tips — all written by people who actually live in Thailand.
No spam. Unsubscribe anytime. We never share your email.