Vientiane, the capital of Laos, features a tropical savanna climate with two distinct seasons: a hot, wet monsoon period and a cooler, dry season. The city is hot year-round, with average highs ranging from 30°C in winter to 37°C in late spring. Rainfall is abundant during the wet season, while winters are sunny and comfortable for travel.
The best times to travel section shows how the months compare for a visit, so you can find the time of year that fits what you want to do.
Background colours of the months:
The colour shows the typical temperature: yellow (hot), green (mild) and blue (cold). How strong the colour is shows the travel season: full colour means high season, soft colour means shoulder season and soft-striped means off season.
Weather symbols:
Each month has one symbol showing what the weather is typically like, such as hot and sunny, freezing or a rainy or snowy season. Use them to quickly spot months that match the weather you want, or to avoid the ones that don't.
Crowdedness:
The people icon shows how busy the place usually is. The more people, the more crowded it gets.
Additional notes:
The grey info boxes point out special things worth knowing, like recurring weather issues or seasonal events.
Vientiane’s climate is shaped by its tropical location and the influence of the Mekong River. The city experiences two main seasons: a dry season from November to April and a wet season from May to October. Summers (March–May) are extremely hot, with average highs reaching 35–37°C in April. Humidity increases as the wet season approaches, and heatwaves above 40°C are possible. The rainy season (May–October) brings heavy, frequent downpours, especially from June to September, when monthly rainfall can exceed 300 mm and humidity peaks above 80%. Despite the rain, there are still sunny intervals, and temperatures remain warm, with daytime highs around 31–33°C and nights rarely dropping below 24°C.
Winters (November–February) are drier, cooler, and more comfortable, with average highs of 29–31°C and lows of 16–20°C. Rainfall is minimal, humidity drops, and skies are often clear, making this the best time for sightseeing and outdoor activities. Sunshine is abundant year-round, with 8–11 hours per day in the dry season and slightly less during the wettest months. Winds are generally light, though brief storms can bring gustier conditions. Vientiane receives about 1,400–2,000 mm of rain annually and enjoys over 2,200 hours of sunshine, with daylight ranging from 11 hours in winter to over 13 hours in summer. Snow is unknown, and flooding can occur during the peak rainy months.
| Average climate data for Vientiane, Laos | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | 29 | 30 | 33 | 34 | 33 | 32 | 31 | 31 | 31 | 31 | 30 | 28 | 34 |
| Average minimum temperature (°C) | 16 | 18 | 22 | 24 | 25 | 25 | 25 | 25 | 24 | 23 | 19 | 17 | 16 |
| Average precipitation (mm) | 8 | 13 | 34 | 85 | 245 | 276 | 268 | 339 | 300 | 78 | 11 | 2 | 1,661 |
| Average rainfall days (days) | 1 | 2 | 4 | 8 | 15 | 18 | 20 | 21 | 17 | 9 | 2 | 1 | 117 |
| Average relative humidity (%) | 70 | 68 | 65 | 70 | 78 | 83 | 82 | 83 | 82 | 78 | 73 | 70 | 75 |
| Average daily daylight hours (h) | 11 | 11 | 12 | 12 | 13 | 13 | 13 | 12 | 12 | 11 | 11 | 11 | 12 |
| Average daily sunshine hours (h) | 8 | 7 | 7 | 7 | 6 | 5 | 4 | 4 | 4 | 8 | 7 | 8 | 6 |
| Average UV index | 9 | 11 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 11 | 9 | 8 | 11 |
The best time to visit Vientiane is from November to February, when temperatures are warm (29–31°C), humidity is lower, and rainfall is minimal. These months offer clear skies, abundant sunshine, and comfortable conditions for exploring temples, markets, and the riverside. This is also the peak tourist season, so expect more visitors and higher accommodation prices.
The least favourable time to visit is from June to September, during the peak of the rainy season. Heavy, frequent downpours, high humidity, and the risk of flooding can make outdoor activities challenging. March and April are also difficult for some travellers due to extreme heat, with daytime highs often above 35°C.
Vientiane’s annual average temperature is about 28°C. January is the coolest month (highs 29–30°C, lows 16–18°C), while April is the hottest (highs 36–37°C, lows 24–26°C).
Vientiane receives about 1,400–2,000 mm of rain annually, with most falling from May to September. Snow is unknown. The wettest months are July and August, with frequent heavy downpours.
Vientiane enjoys over 2,200 hours of sunshine per year. The sunniest months are in the dry season (November–April), with up to 11 hours of sunshine daily. Wet season months are cloudier, but still see sunny intervals.
The best time for outdoor activities is from November to February, when temperatures are warm, humidity is lower, and rain is rare. These months are ideal for sightseeing, cycling, and riverside walks.
Vientiane is not suitable for winter sports. Temperatures are warm year-round, and snow does not occur. The city is best for cultural exploration and tropical outdoor activities.
Swimming outdoors is comfortable from March to October, when air temperatures range from 32–37°C. Many hotels have pools, but natural swimming is limited due to river conditions, especially in the rainy season.
Pack light, breathable clothing, sun protection, and a hat for the hot season. Bring a rain jacket and waterproof shoes if visiting during the wet season. Light layers are useful for cooler winter mornings and evenings.
The warmest month, with the highest average maximum temperature, is April (34.2 °C). The month with the lowest average maximum temperature is December (28.2 °C). Overall, the average maximum temperature over the whole year is 31 °C.
The month with the highest average minimum temperature is June (24.9 °C). The coldest month, with the lowest average minimum temperature, is January (16.4 °C). Overall, the average minimum temperature over the whole year is 21.8 °C.
The wettest month, with the highest amount of precipitation, is August (339.5 mm). The driest month, with the least amount of precipitation, is December (2.5 mm). Over the whole year there are 1,660.6 mm of rainfall on average.
The month with the most days of rain is August (21.1 days). The month with the fewest days of rain is December (0.9 days). Over the whole year there are 117.5 days of rain on average.
The month with the highest average relative humidity is August (83.5 %). The month with the lowest average relative humidity is March (65.1 %). The overall average relative humidity over the whole year is 75.2 %.
The months with the longest days, so the most daylight, are June and July (Average daylight: 13 h). The months with the shortest days, so the least daylight, are January and December (Average daylight: 11 h). Over the whole year there are 11.9 h of daylight per day on average.
The month with the most sunshine per day is October (Average sunshine: 8.1 h). The month with the least sunshine per day is August (Average sunshine: 3.9 h). Over the whole year there are 6.2 h of sunlight per day on average.
The months with the highest average UV index are March, April, May, June, July, August and September (UV index: 12). The month with the lowest average UV index is December (UV index: 8). Over the whole year the average UV index is 11.
