Season by season
Cool & dry season
November to February brings clear skies, warm days and cool nights — cold at altitude, where a fleece is essential before dawn. It is the best time for trekking and cycling and the busiest time of year, especially around the November festivals and New Year.
Hot season
March to May is hot, with city temperatures reaching the high 30s. From about late February to mid-April smoke from agricultural burning often makes the air unhealthy and reduces mountain views to a haze. Songkran in mid-April is celebrated more exuberantly here than anywhere else in Thailand.
Rainy season & sea conditions
The rains arrive around June and last until October. Mornings are often dry, the forest and rice terraces are at their greenest and waterfalls and rapids are at full strength. Trails are muddy and some, including Kew Mae Pan, close for the season.
Month by month
| Month | Avg high | Avg low | Rainfall | Crowds |
|---|---|---|---|---|
| January | 30°C | 15°C | 10 mm | Very busy |
| February | 33°C | 16°C | 10 mm | Very busy |
| March | 35°C | 20°C | 20 mm | Busy |
| April | 36°C | 23°C | 55 mm | Busy |
| May | 34°C | 24°C | 150 mm | Quiet |
| June | 33°C | 24°C | 120 mm | Quiet |
| July | 32°C | 24°C | 150 mm | Busy |
| August | 32°C | 24°C | 220 mm | Busy |
| September | 32°C | 23°C | 210 mm | Quiet |
| October | 31°C | 22°C | 120 mm | Busy |
| November | 30°C | 19°C | 45 mm | Very busy |
| December | 29°C | 16°C | 15 mm | Very busy |
Temperatures and rainfall are approximate long-term averages for the nearest weather station; individual years vary, and mountain areas are cooler than the figures shown.
Festivals & events
- February: The Chiang Mai Flower Festival, with a parade of floats covered in blooms.
- April: Songkran (13–15 April), three days of water fights around the moat.
- November: Yi Peng and Loy Krathong, when lanterns rise over the city and floats are released on the Ping River.
- December–January: Cherry blossom on the high slopes of Doi Suthep-Pui and Doi Inthanon, and the coldest nights of the year.
Our advice
Come between November and early February for the best trekking weather, or in July and August for green landscapes, strong rivers and fewer visitors. Avoid March and early April if clean air matters to you. Our Thailand seasons guide compares the north with the coasts month by month.
