Vientiane climate — normals and trends
Vientiane (Laos) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 26.1 °C and it receives 1,960 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 (28.7 °C on average) and the coldest is January (21.9 °C). Rainfall peaks in August.
Vientiane averages 0 frost days, 245 hot days (≥ 30 °C) and 172 rainy days per year.
Vientiane has warmed by +1.9 °C between 1940 and 2025, or +0.23 °C per decade. This trend is statistically significant.
The hottest day of the period reached 42.9 °C (on 6 May 2023) and the coldest 4.5 °C (on 12 January 1955).
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
VientianeVientiane Prefecture
- coords
- 17.97°, 102.60°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
26.1°C
Average daily high
31.2°C
Average daily low
22.1°C
Annual rainfall
1,960mm
Sunshine / day
9.5h
Mean relative humidity
76%
Average peak wind
9.5km/h
Seasonal range
6.8°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
245 d/yr
Rainy days (≥ 1 mm)
172 d/yr
Annual snowfall
0.0 cm
Average feels-like high
35.7 °C
Average feels-like low
25.6 °C
Average peak gust
26.6 km/h
Tropical nights (≥ 20 °C)
271 d/yr
Solar radiation
17.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.9 °C
since 1940
+0.2 °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
42.9 °C
6 May 2023
Coldest day
4.5 °C
12 January 1955
Wettest day
166 mm
27 June 1983
Windiest day
29.2 km/h
13 March 2009
Strongest gust
67.3 km/h
22 October 1952
Hottest feels-like
48.8 °C
7 May 2023
Coldest feels-like
1.4 °C
12 January 1955
Sunniest day
12.8 h
12 July 1941
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 | 28.4 °C | -0.2 °C | 0 mm | -11 mm |
| Feb | 31.6 °C | +0.5 °C | 36 mm | +20 mm |
| Mar | 33.8 °C | +0.1 °C | 4 mm | -37 mm |
| Apr | 35.4 °C | +0.9 °C | 65 mm | -24 mm |
| May | 33.8 °C | +1.1 °C | 182 mm | -81 mm |
| Jun | 33.0 °C | +1.1 °C | 287 mm | -43 mm |
| Jul | 31.2 °C | -0.2 °C | 429 mm | +95 mm |
| Aug | 32.3 °C | +1.3 °C | 321 mm | -71 mm |
| Sep | 31.8 °C | +0.9 °C | 263 mm | -74 mm |
| Oct | 32.3 °C | +1.6 °C | 63 mm | -55 mm |
| Nov | 29.1 °C | -0.6 °C | 48 mm | +25 mm |
| Dec | 29.4 °C | +1.3 °C | 16 mm | +10 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 Vientiane?
Vientiane has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 26.1 °C and it receives 1,960 mm of precipitation per year.
What is the hottest day ever recorded in Vientiane?
The hottest day measured in Vientiane between 1940 and 2025 was 6 May 2023, reaching 42.9 °C.
What is the coldest day in Vientiane?
The coldest day measured in Vientiane between 1940 and 2025 was 12 January 1955, at 4.5 °C.
Does it snow in Vientiane?
Almost never: Vientiane sees virtually no snow, with about 0 frost days per year.
Has the climate of Vientiane warmed?
Yes: Vientiane warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Vientiane?
The wettest day measured in Vientiane between 1940 and 2025 was 27 June 1983, with 166 mm of rain in 24 hours.
What was the windiest day in Vientiane?
The windiest day measured in Vientiane between 1940 and 2025 was 13 March 2009, with winds reaching 29.2 km/h.
What is the warmest month in Vientiane?
The warmest month in Vientiane is April (28.7 °C on average); the coldest is January (21.9 °C).
How much does it rain in Vientiane?
Vientiane receives on average 1,960 mm of precipitation per year, spread over about 172 rainy days.
Is it sunny in Vientiane?
Vientiane gets on average 9.5 hours of sunshine per day, roughly 3,468 hours per year over 1940-2025.
Are there tropical nights in Vientiane?
Yes: Vientiane has on average 271 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Vientiane?
In Vientiane, between 1940 and 2025, the highest apparent temperature reached 48.8 °C on 7 May 2023, and the lowest was 1.4 °C on 12 January 1955.
Compare Vientiane with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Vientiane