Similar to Cambodia or South Vietnam, Laos has two distinct seasons – the wet and the dry.
Laos‘ wet season runs from around May to October, and the wet season is characterized by a downpour for a few hours each day rather than all-day torrential downpours as with many Southeast Asian countries. While the rainy season tends to strike Laos pretty much uniformly, there are a couple of regional oddities. Laos’ wet season tends to hit Phongsali a little early due to it catching a bit of rain from southern China, while Hua Phan and Xieng Khuang tend to get a little early rain from Vietnam.
On the other hand, Laos’ dry season has two distinct sub-sections – the cool dry season and then the hot dry season — the former is one of the most popular times to visit Laos, the later less so. The cool dry season runs from November to February and the hot dry season from March to April. What the hot season lacks in length it makes up in ferocity — they don’t call it the hot season for nothing. The cool dry season on the other hand is an excellent time to go. Temperatures are relatively low, the air is cleaner and, particularly in November and December, the rivers are high enough to make river travel a breeze. Not surprisingly, this period in Laos is the peak season.