Chiang Mai is conveniently located in the rolling foothills of the Himalayas. This leads to a much milder climate than that of Bangkok and Southern Thailand. Chiang Mai’s climate is one of its best attractions; the mild climate allows for open-air restaurants, fantastic outdoor adventure opportunities, and a low energy bill (aircon really isn’t necessary).
There are three distinct seasons in Chiang Mai: the Rainy Season, the Cold Season, and the Dry Season. It is possible to climb during all of these, each offering different benefits.
The Cold Season: October – February
This is an ideal time to visit Chiang Mai. Beginning in October, the rains stop and the weather begins to cool. The days are mild with comfortable temperatures, and the nights are chilly, often requiring a warm hat and a light jacket.
Translation: this is perfect climbing weather! It generally does not rain during these months, so you can climb any day, and the cold mornings are perfect for sending hard projects!
The sun is lower in the sky during this time, so South-facing crags can get a little warm, but if you chase the shade, you can have goosebumps all day.
Be sure to bring a warm jacket and a hat – open-air transport can be downright frigid!
The Dry Season: March – May
This is also known as The Hot Season for good reason. Though it is hot, the sun rises higher in the sky, so South-facing exposure is less intense, making it possible to climb all day, even in the sun.
There are plenty of shaded crags and bamboo huts at Chiang Mai’s crag so even when it’s hot, you can stay cool all day. The heat is a dry heat, and it is often breezy this time of year, so you won’t be sweating buckets like in other parts of Thailand.
The Thai New Year Songkran Festival provides a welcome reprieve from the heat in the middle of April by turning Chiang Mai into one giant water fight.
You can also get out of the heat by escaping underground into the cool temps of the crag’s underground labyrinth of caves.
The Rainy Season: June to September
Don’t worry… it doesn’t rain all the time.
Chiang Mai is located pretty far North, and therefore does not experience tropical rain storms. While it can rain every day in Chiang Mai, it often rains in the afternoon for short periods of time. These rains dry quickly and make it comfortable at night.
The rain is often welcomed as pollution builds up between November and May and the rain cleans out the valleys and brings out brilliant blues, greens and other colors.
It is possible to climb during the rainy season, and even during rain if you seek out the steeper crags or the routes inside of caves! Be sure to bring a rain jacket and perhaps a backpack cover in case you get caught in a downpour.