Climate Overview
Chiang Mai has a tropical-savanna climate with a distinct three-season pattern: cool Nov–Feb (17–18°C lows, under 20mm rain), hot-dry Mar–Apr (37°C highs, smoky from crop burning), and wet May–Oct (peaking 262mm in Sep). Nov–Feb is the clear winner — the rest trades heat, smoke, or rain.
Monthly Climate
Temperature range, rainfall, and humidity by month
Monthly Data
| Month | High | Low | Rainfall | Humidity |
|---|---|---|---|---|
| Jan | 30.1° | 15.7° | 1mm | 70% |
| Feb | 34.1° | 19° | 34mm | 64% |
| Mar | 36.8° | 21.5° | 1mm | 59% |
| Apr | 36.7° | 24.3° | 111mm | 64% |
| May | 34.5° | 24.5° | 375mm | 76% |
| Jun | 33.9° | 25.1° | 269mm | 83% |
| Jul | 32.6° | 24.6° | 357mm | 87% |
| Aug | 33.1° | 24.3° | 393mm | 86% |
| Sep | 31.9° | 23.9° | 288mm | 84% |
| Oct | 32.2° | 22.9° | 97mm | 79% |
| Nov | 28.9° | 19.9° | 173mm | 78% |
| Dec | 29.3° | 17.8° | 2mm | 74% |
When to Visit
Experiences to seek out and peak periods to plan around
Experiences & Highlights
Sky lanterns rise over the moat and krathongs float on the Ping river around the Nov full moon (4–6 Nov 2025); coincides with dry cool-season weather — 31°C highs, 51mm rain, humidity dropping to 80%.
18–21°C nights and 30–33°C days make walks to Doi Suthep, Wat Phra Singh and the Old City moat comfortable; December averages just 13mm rain.
Thai New Year water fights take over Tha Pae Gate and the moat 13–15 Apr; falls in the year's hottest stretch (37.7°C highs) so the soaking is welcome.
Monsoon peaks (220–262mm/month, 86–87% humidity) swell Mae Sa and Bua Tong sticky waterfalls; cooler 32–33°C highs and fewer crowds on Doi Inthanon trails.
Peak Periods & Travel Advisories
Old-City guesthouses sell out 3–6 months ahead and lantern-release tickets run 3000–8000 THB; flights from Bangkok double in price around the full moon.
Nationwide holiday: moat roads close to through traffic, many shops shut, flights sell out; hotel rates inside the Old City spike 50–80%.
Agricultural field burning across N. Thailand, Laos and Myanmar pushes PM2.5 well above WHO limits — often hazardous in March despite only 13mm rain and 52% humidity. N95 masks recommended; viewpoints like Doi Suthep vanish in haze.
Thailand Destination Comparison
Compare climate across destinations in Thailand
| City | Avg High | Avg Low | Annual Rain | Season Overview |
|---|---|---|---|---|
🇹🇭 Chiang Mai | 33° | 22° | 2100 mm | |
🇹🇭 Bangkok | 33° | 25° | 1716 mm | |
🇹🇭 Phuket | 33° | 25° | 2735 mm |
Official Resources
Government portals and tourism boards for Chiang Mai, Thailand