Weather in Chiang Mai: Climate, Seasons, and Average Monthly Temperature

Forget the heat of Phuket and the humidity of Bangkok; the weather Chiang Mai is just right. Those cooler temperatures are thanks to Chiang Mai's higher elevation close to Thailand's tallest mountains.

The best time to visit Chiang Mai coincides with the lowest overall temperatures and humidity, which occur between November and February. This is also peak tourist season, when festivals like Loi Krathong and the Chiang Mai Flower Festival draw tourists from all over the region, attracted by Chiang Mai’s seasonally crisp air and festive atmosphere.

The area is less fun to visit during the hot, dry season between March and June and during its “smoky season” in March caused by local farmers burning off chaff left over from the last harvest. Things brighten up a bit when the rainy season begins in July; greener surroundings and gushier (if muddier) waterfalls make up for the higher humidity and the increased chances of washed-out roads.

The long and short of it is: cooler weather also means more tourists, but don’t rule out a rainy-season visit to this gorgeous northern Thai city.

Fast Climate Facts

• Hottest Month: April: (84 F / 29 C)
• Coldest Month: December (70 F / 21 C)
• Wettest Month: August (9.4 inches)
• Driest Month: February (0.1 inches)
• Windiest Month: May (4.3 mph)

For a more detailed look at the local climate from month to month, read our overview of weather in Thailand.

Burning Season in Chiang Mai

The dry, hot months starting from late February coincide with the “burning season” in Chiang Mai, when farmers in Northern Thailand burn any leftover chaff from their harvest, creating a noxious haze that’s bottled in by the nearby mountains.

Burning leftover stalks from the corn and rice harvest both clears the fields and helps fertilize them ahead of the rainy season. These fires also transform Chiang Mai into one of the world’s most polluted cities for those months; daily average particulate matter concentrations (PM10) can go as high as 292 micrograms per cubic meter, up from a World Health Organisation (WHO) ideal of 50 micrograms per cubic meter or less.

Chiang Mai’s location in the middle of mountains only aggravates the situation. Surrounding peaks like Doi Suthep, Doi Saket, and Doi Inthanon help bottle up the smoke, covering parts of the city in fine ash dust and increasing hospital admissions for sore throats, bronchial infections, and heart ailments. Unfortunately, any visitors on these months will have to bear the situation until July, when the rainy season washes away the smog.

Cool, Dry Season in Chiang Mai

The crisp, cool air that Chiang Mai enjoys from November to February allows tourists to walk around the night markets and hike in the mountains without breaking a sweat.

Temperatures peak at around 87 F in the daytime, dropping as low as 59 F after dark in the city and 50 F in the mountains. Visits to temples like Wat Prathat Doi Suthep feel almost effortless, even when climbing up the interminable steps leading there. Thai festivals like Loi Krathong (around November) are a joy to experience, as the cool air contrasts with the heat from the candles that brighten the krathong set in the river.

What to pack: Customize your packing list to match the weather. bring a jacket against the cooler air of the season; if you’re hiking in the mountains, bring cool-weather clothing. If you’re staying in the city, bring comfortable shoes as you’ll be doing a lot of walking in this conducive weather!

Average temperatures and rainfall by month:

• November: 74 F / 23 C; 1 inch
• December: 70 F (21 C; 0.4 inch
• January: 71 F (22 C; 0.3 inch
• February: 76 F (24 C; 0.1 inch

Hot, Humid Season in Chiang Mai

From March to May, the transition to a hotter, humid climate turns Chiang Mai into a sweatbox. It's not as bad as the worst that Bangkok might bring, but visitors from temperate climes will still feel like they’re swimming in the humid air.

High temperatures and sporadic bursts of rain characterize the hot, humid season in Chiang Mai – as does a copious amount of smoke rustled up by local farmers burning away the remains of this year’s harvest.

Temperatures soaring as high as 92 F in the daytime ensure that Chiang Mai is not the most heavily-touristed during this time of year; visitors who do arrive in this season flee almost immediately for the mountains, where they can get some relief from the lowland heat and humidity, and partially from the smoke as well.

What to pack: Sweat-wicking shirts and high-UV hats or sunscreen to ward off perspiration and heat; bring a water bottle to refresh yourself in the daytime. An N95 mask will help with the smog

Average temperatures and rainfall by month:

• March: 81 F / 27 C; 0.5 inch
• April: 84 F / 29 C; 1.1 inch
• May: 81 F / 27 C; 4.3 inches

Rainy Season in Chiang Mai

Relief from the heat and smoke finally drops on Chiang Mai, quite literally, in the form of heavy rains between June and October. Average temperatures in the rainy season reach a more manageable 89 F in the daytime, dropping to 73 F after dark.

The daily rains can dampen your plans, especially if washed-out trails cancel your hiking plans. Luckily the rains generally fall only in the late afternoon or evening early in the season, and while intense, the rains peter out after an hour or so. Once the rains finish, the streets feel cleaner, the outdoors greener, and the air a little cooler (if not less humid) than before.

As the rains intensify in August and September, national parks close their doors to tourists. Flash floods might affect remote areas. Consider any countryside day trips carefully during this time of year.

What to pack: Rain-friendly shoes; an umbrella; windbreaker. Pack electronics in water-resistant bags.

Average temperatures and rainfall by month:

• June: 79 F / 26 C; 5.1 inches
• July: 78 F / 26 C; 7.3 inches
• August: 77 F / 25 C; 9.4 inches
• September: 77 F / 25 C; 9.3 inches
• October: 76 F / 24 C); 4.8 inches

Average Monthly Temperature, Rainfall, and Humidity