- Snowfall
- none—tropical climate does not support snow formation
- Driest Month
- February (~4 mm rainfall)
- Wettest Month
- August (~240–260 mm rainfall)
Good to know
Good to Know
- December–January offer the most comfortable weather: cool nights (15–20°C (59–68°F)), warm days (21–30°C (70–86°F)), and almost zero rain.
- Avoid March–April if you dislike extreme heat; daytime temps regularly exceed 35°C (95°F), and visibility can be poor from smoke.
- May–October is very wet; bring rain gear and expect daily downpours in August–September. Locals call this the 'green season' due to lush landscapes.
- Humidity is high year-round but peaks at 80%+ during July–September; dress in breathable, moisture-wicking fabrics.
- UV index is extreme (12–14) from March–September; sunscreen and sun protection are essential.
- Snowfall never occurs; even the coldest winter nights rarely dip below 10°C (50°F).
Seasons
Cool/Dry Season
- Months
- November–February
- Humidity
- 52–75% relative humidity
- Rainfall Range
- minimal (4–54 mm per month)
- Description
- Best time to visit. Cool, dry weather ideal for outdoor activities.
Temperature Range
- Daytime Celsius
- 21–30
- Nighttime Celsius
- 15–20
- Daytime Fahrenheit
- 21–30
- Nighttime Fahrenheit
- 15–20
Hot/Dry Season
- Months
- March–April
- Humidity
- 47–57% relative humidity
- Rainfall Range
- minimal to light (4–162 mm per month)
- Description
- Very hot and dry. March–April are the hottest months before monsoon arrives.
Temperature Range
- Daytime Celsius
- 30–36.5
- Nighttime Celsius
- 21–25
- Daytime Fahrenheit
- 30–36.5
- Nighttime Fahrenheit
- 21–25
Rainy/Monsoon Season
- Months
- May–October
- Humidity
- 73–86% relative humidity
- Rainfall Range
- 162–260 mm per month
- Description
- Southwest monsoon brings heavy, frequent rainfall. Humid and green landscapes. Highest rainfall in August–September.
Temperature Range
- Daytime Celsius
- 30–33
- Nighttime Celsius
- 23–25
- Daytime Fahrenheit
- 30–33
- Nighttime Fahrenheit
- 23–25
Snowfall
none—tropical climate does not support snow formation
Driest Month
February (~4 mm rainfall)
Wettest Month
August (~240–260 mm rainfall)
Sunshine Hours
- Annual Total
- ~2,500–3,400 hours per year
- Sunniest Months
- March–May (9–10 hours daily)
- Cloudiest Months
- July–September (4–8 hours daily)
Annual Rainfall
1,100–1,200 mm (43–47 inches)
Air Quality Note
Air quality can deteriorate in March–April due to agricultural burning in neighboring regions, especially upper Thailand.
Temperature Extremes
- Absolute Maximum
- 42°C (107°F) in extreme heat
- Absolute Minimum
- 4°C (39°F) in rare cold waves
Peak Months Best Weather
Peak Months Best Weather
- December
- January
Off Peak Months Worst Weather
Off Peak Months Worst Weather
- August
- September
AI-generated estimateData refreshed July 2026
Sources cited for this category
These are the sources cited in this climate & weather research for this city. Individual figures may not each trace to one of them.
More About Chiang Mai
Data last updated July 2026 · Verify anything important.