The annual monsoon cycle that affect of mainland Southeast Asia produce a dry and wet monsoon climate with three basic seasons for most of Laos. The southwest monsoon arrives in Laos between May July and lasts into November.
The monsoon is followed by a dry period (from November to May), beginning with lower relative temperatures and cool breezes created by Asia’s northeast monsoon (which by passes most of Laos), lasting until mid February. Exceptions to this general tern include Xieng Khuang, Hua and Phongsali Provinces, which receive rainfall coming from Vietnam and China during the months Apr and May.
Rainfall varies substantially according to altitude with the highland of Vientiane, Bolikhamsai, Khammuan and eastern Champasak Provinces receiving.
Temperature is also varying according to altitude. In the humid, low lying Mekong River valley, temperature range from 15ºC to 38ºC while the mountain of Xieng Khoang can drop to 0ºC.
Tags: Climate Charts