Vientiane climate
Vientiane (Laos) has a tropical savanna (dry winter) climate (Köppen Aw). The average temperature over the year is 26 °C79 °F, and about 1,215 mm48 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Vientiane climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 2883 | 1559 | 2271 | 80.3 |
| Feb | 3290 | 1864 | 2577 | 130.5 |
| Mar | 3595 | 2271 | 2883 | 351.4 |
| Apr | 3798 | 2576 | 3187 | 612.4 |
| May | 3494 | 2577 | 3085 | 1686.6 |
| Jun | 3290 | 2476 | 2883 | 1706.7 |
| Jul | 3188 | 2475 | 2882 | 2038.0 |
| Aug | 3086 | 2475 | 2781 | 2459.7 |
| Sep | 3087 | 2374 | 2780 | 2048.0 |
| Oct | 3086 | 2170 | 2678 | 853.3 |
| Nov | 2984 | 1865 | 2474 | 160.6 |
| Dec | 2781 | 1559 | 2170 | 60.2 |
| Year | 3798 | 1559 | 2679 | 1,21548 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 65% | 33% | 4.8 | 11:10 |
| Feb | 57% | 33% | 5.2 | 11:32 |
| Mar | 52% | 47% | 5.2 | 11:00 |
| Apr | 55% | 58% | 5.7 | 12:32 |
| May | 70% | 82% | 5.5 | 12:58 |
| Jun | 79% | 90% | 5.1 | 13:12 |
| Jul | 82% | 92% | 4.8 | 13:06 |
| Aug | 85% | 93% | 4.6 | 12:44 |
| Sep | 85% | 84% | 4.7 | 12:13 |
| Oct | 82% | 59% | 4.9 | 11:42 |
| Nov | 76% | 40% | 4.9 | 11:16 |
| Dec | 71% | 32% | 4.6 | 11:03 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Vientiane is like
The warmest month is April, with an average high of 37 °C98 °F and a low of 25 °C76 °F. The coldest is December, when highs average 27 °C81 °F and lows 15 °C59 °F. There is a clear seasonal cycle, with 9.8 °C17.7 °F between the average temperature of the warmest and the coolest month.
It is wet, with about 1,215 mm48 in of precipitation per year. The wettest three-month stretch is July–September, which brings 54% of the annual total. Months with less than 20 mm0.8 in on average: November–February. The wettest month is August (245 mm9.7 in), the driest is December (6 mm0.2 in).
Relative humidity ranges from 52% in March to 85% in August. The clearest skies (lowest average cloud amount, 32%) are typical of December. Average wind speed near the ground ranges from 4 km/h (3 mph) in September to 6 km/h (4 mph) in March. Daylight lasts from about 11.1 hours in December to 13.2 hours in June.
Best time to visit Vientiane
Based on these averages, the most comfortable months for sightseeing and outdoor activities are November–January: average highs of 27 °C81 °F to 29 °C84 °F with 6 mm0.2 in to 16 mm0.6 in of precipitation per month.
The most challenging month is August, which is hot, with average highs of 30 °C86 °F, very wet (245 mm9.7 in) and humid (85% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Vientiane
- Wetter months (May–September) — highs 3086 to 34 °C94 °F, lows 2374 to 25 °C77 °F, about 198 mm7.8 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water and an umbrella or light rain jacket.
- Drier months (October–April) — highs 2781 to 37 °C98 °F, lows 1559 to 25 °C76 °F, about 32 mm1.3 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water.
How Vientiane compares
Compared with Thanh Hóa, about 391 km to the northeast, Vientiane is on average 2.1 °C3.8 °F warmer and receives 25% less precipitation (1,215 mm48 in vs 1,613 mm63 in). The difference is largest in March (6.4 °C11.4 °F warmer).
Places in other countries with the most similar temperature and rainfall pattern: Udon Thani (Thailand, Aw), Khon Kaen (Thailand, Aw) and Lampang (Thailand, Aw).
Nearby places
- Udon Thani 64 km · 26 °C79 °F · 1,323 mm52 in
- Khon Kaen 171 km · 27 °C80 °F · 1,364 mm54 in
- Savannakhet 277 km · 26 °C79 °F · 1,227 mm48 in
- Lampang 330 km · 27 °C80 °F · 1,189 mm47 in
- Vinh 336 km · 25 °C78 °F · 1,774 mm70 in
- Nakhon Ratchasima 337 km · 27 °C80 °F · 1,220 mm48 in
- Nghi Sơn 372 km · 24 °C75 °F · 1,701 mm67 in
- Ubon Ratchathani 387 km · 27 °C81 °F · 1,523 mm60 in
Frequently asked questions
What is the warmest month in Vientiane?
April is the warmest month in Vientiane, with an average high of 37 °C (98 °F) and an average low of 25 °C (76 °F).
What is the coldest month in Vientiane?
December is the coldest month, with an average high of 27 °C (81 °F) and an average low of 15 °C (59 °F).
When does it rain the most in Vientiane?
August is the wettest month with about 245 mm (9.7 in) of precipitation; December is the driest with about 6 mm (0.2 in).
What is the best time to visit Vientiane?
Judging by long-term averages, the most comfortable months are November–January.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.