Thailand Weather & Seasons

The best time depends on the specific destination you plan to visit and your personal travel preferences. For most of the country (Bangkok, Chiang Mai, Phuket, Krabi), the cooler, drier months from November to February provide the most settled weather and comfortable temperatures. However, for Gulf islands like Koh Samui and Koh Tao, July and August offer a popular sunny window, while the late-year months of October–November bring their heaviest rain.

Across most of mainland Thailand and the Andaman coast (Phuket, Krabi), the rainy season runs roughly from May/June through October, driven by the southwest monsoon. In the lower Gulf of Thailand (Koh Samui, Koh Phangan, Koh Tao), the monsoon season peaks later, between October and December, driven by the northeast monsoon.

No. In Thailand, tropical rain typically arrives in short, concentrated bursts lasting 1 to 2 hours—often in the late afternoon or evening—followed by clearing skies. While multi-day continuous overcast rain can occur during tropical low-pressure systems, most rainy-season days still offer several hours of sunshine.

No. This is one of the most common misconceptions among travellers. Phuket is on the west coast (Andaman Sea) and receives its heaviest monsoon rains and rough seas between May and October. Koh Samui is in the Gulf of Thailand and experiences its wettest period later, from October to December. During July and August, Samui often enjoys sunny beach weather while Phuket is rainier.

March, April, and early May are typically the hottest months across Thailand. Daytime temperatures in Bangkok, Chiang Mai, and the Isaan plains frequently exceed 38°C to 40°C with high humidity before the southwest monsoon arrives to cool the land.

Northern Thailand (including Chiang Mai, Chiang Rai, and Mae Hong Son) can experience elevated levels of PM2.5 air pollution and haze during the late dry season. This is caused by a combination of agricultural burning, seasonal forest fires, geographic valley topography, and stagnant atmospheric conditions. The exact timing and severity vary considerably year to year, but elevated smoke levels most commonly occur between February and April.

For southern beaches, Bangkok, and central Thailand, lightweight tropical clothing is sufficient year-round. However, if you are visiting Northern Thailand (Chiang Mai, Chiang Rai) or high-altitude mountain parks between November and February, morning and evening temperatures can drop to 12–16°C (and below 10°C on summits like Doi Inthanon), so a light fleece or jacket is highly recommended. Long-distance air-conditioned buses, trains, and malls can also be brisk.

Use the interactive destination selector above on this page to view current temperature, feels-like temperature, humidity, and real-time conditions, or click the direct forecast link to view detailed external weather forecasts and meteorological radar.