Laos Climate

Most of the year is hot and humid. Laos enjoys a tropical climate with two distinct seasons. The rainy season is from the beginning of May to the end of September, and the dry season is from October through April. The yearly average temperature is about 28 degrees Celsius, rising to a maximum of 38 degrees Celsius during April and May.

In Vientiane a minimum temperature of 19 degrees Celsius is to be expected during January. In mountainous areas, however, temperature drops to as low as 14-15 degrees Celsius during the winter months, and during cold nights, can easily reach the freezing point. The average precipitation is highest in Southern Laos, where the Annamite Mountains receive over 3,000 mm. annually. In Vientiane rainfall is about 1,500-2,000 mm., and in the Northern provinces only 1,000-1,500 mm.

When to go

The best time for visiting most of Laos is between November and February, when it rains the least and is not too hot. It’s also Laos’s main season for both national and regional bun (festivals).

If you plan to focus on the mountainous northern provinces, the hot season (from March to May) and early rainy season (around June) is not bad either, as temperatures are moderate at higher elevations. Southern Laos, on the other hand, is best avoided from March to May, when day-time temperatures break into the 40s and nights aren’t much cooler.

The rainy season is not as bad as you might think. While it will rain – very heavily – the downpours are often fairly brief and can be bracketed by long periods of sunshine. The rains also clear dust from the skies and land, making everything clearer and brighter. Of course, there are downsides; unsealed roads can become quagmires and extensive travel in remote areas like Salavan, Phongsali and Sainyabuli might be impossible. River travel can be a good alternative during these months. If you intend to travel extensively by river, November is the best; flooding has usually subsided yet river levels are still high enough for maximum navigability. Between January and June, low water can make navigating some rivers difficult.

December to February and August are the peak tourist times. January, in particular, is very busy and booking ahead is advisable.