Chiang Mai climate — normals and trends
Chiang Mai (Thailand) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 25.5 °C and it receives 1,051 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is April (29.3 °C on average) and the coldest is December (20.7 °C). Rainfall peaks in September.
Chiang Mai averages 0 frost days, 242 hot days (≥ 30 °C) and 138 rainy days per year.
Chiang Mai has warmed by +2.2 °C between 1940 and 2025, or +0.26 °C per decade. This trend is statistically significant.
The hottest day of the period reached 42.8 °C (on 16 April 1983) and the coldest 3.3 °C (on 26 December 1999).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
Chiang MaiChiang Mai
- coords
- 18.79°, 98.98°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
25.5°C
Average daily high
31.5°C
Average daily low
20.8°C
Annual rainfall
1,051mm
Sunshine / day
9.7h
Mean relative humidity
72%
Average peak wind
8.0km/h
Seasonal range
8.6°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
242 d/yr
Rainy days (≥ 1 mm)
138 d/yr
Annual snowfall
0.0 cm
Average feels-like high
35.1 °C
Average feels-like low
23.6 °C
Average peak gust
24.1 km/h
Tropical nights (≥ 20 °C)
238 d/yr
Solar radiation
17.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.2 °C
since 1940
+0.3 °C per decade · r² = 0.72 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
42.8 °C
16 April 1983
Coldest day
3.3 °C
26 December 1999
Wettest day
119 mm
9 September 1961
Windiest day
25.6 km/h
8 May 1975
Strongest gust
66.2 km/h
8 May 1975
Hottest feels-like
45.8 °C
11 May 2016
Coldest feels-like
0.7 °C
26 December 1999
Sunniest day
13.0 h
22 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 28.8 °C | 0.0 °C | 0 mm | -7 mm |
| Feb | 32.4 °C | +0.5 °C | 6 mm | +2 mm |
| Mar | 35.0 °C | +0.2 °C | 0 mm | -13 mm |
| Apr | 35.5 °C | -0.8 °C | 15 mm | -10 mm |
| May | 32.9 °C | -1.2 °C | 163 mm | +59 mm |
| Jun | 32.1 °C | -0.2 °C | 109 mm | -15 mm |
| Jul | 31.2 °C | -0.3 °C | 198 mm | +40 mm |
| Aug | 31.7 °C | +1.0 °C | 213 mm | +0 mm |
| Sep | 31.8 °C | +1.2 °C | 129 mm | -107 mm |
| Oct | 32.0 °C | +1.8 °C | 92 mm | -36 mm |
| Nov | 28.2 °C | -1.0 °C | 123 mm | +91 mm |
| Dec | 29.1 °C | +1.3 °C | 4 mm | -5 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Chiang Mai?
Chiang Mai has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 25.5 °C and it receives 1,051 mm of precipitation per year.
What is the hottest day ever recorded in Chiang Mai?
The hottest day measured in Chiang Mai between 1940 and 2025 was 16 April 1983, reaching 42.8 °C.
What is the coldest day in Chiang Mai?
The coldest day measured in Chiang Mai between 1940 and 2025 was 26 December 1999, at 3.3 °C.
Does it snow in Chiang Mai?
Almost never: Chiang Mai sees virtually no snow, with about 0 frost days per year.
Has the climate of Chiang Mai warmed?
Yes: Chiang Mai warmed by +2.2 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Chiang Mai?
The wettest day measured in Chiang Mai between 1940 and 2025 was 9 September 1961, with 119 mm of rain in 24 hours.
What was the windiest day in Chiang Mai?
The windiest day measured in Chiang Mai between 1940 and 2025 was 8 May 1975, with winds reaching 25.6 km/h.
What is the warmest month in Chiang Mai?
The warmest month in Chiang Mai is April (29.3 °C on average); the coldest is December (20.7 °C).
How much does it rain in Chiang Mai?
Chiang Mai receives on average 1,051 mm of precipitation per year, spread over about 138 rainy days.
Is it sunny in Chiang Mai?
Chiang Mai gets on average 9.7 hours of sunshine per day, roughly 3,540 hours per year over 1940-2025.
Are there tropical nights in Chiang Mai?
Yes: Chiang Mai has on average 238 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Chiang Mai?
In Chiang Mai, between 1940 and 2025, the highest apparent temperature reached 45.8 °C on 11 May 2016, and the lowest was 0.7 °C on 26 December 1999.
Compare Chiang Mai with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Chiang Mai