Laos is a fairly wet country with its tropical monsoon climate. Rainfall is heavy from May to October; it's dry and cool from November to February; and hot and dry in March and April. Usually, the monsoon occurs simultaneously throughout Laos. However, the timing of the monsoon can vary from year to year, so plan your Champasak travel accordingly and book your Champasak hotel in advance. There's even a variance in the amount of rainfall in the different regions. The highest annual rainfall - 3700 mm was noted on the Bolovens Plateau in Champasak Province.
If you're planning your trip to Champasak Province, find out more about the UNESCO Heritage Site at Wat Phou, and see what other highlights of Champasak await!
Despite the high average of precipitation, some years Laos receives only half or even less of the usual rain expected. This causes a considerable dip in yields of rice. Fortunately, droughts like this are often confined only to certain regions, which means that rice production in other parts of the country remain unaffected. Temperatures in Laos along the Mekong River in March and April vary from 40 °C highs to lows of 5 °C or less in January in the Phôngsali and Xiangkhoang uplands.
The annual average temperature in Laos is around 28 °C/82 °F. The maximum is 38 °C/100 °F in April and May. January in Vientiane sees a low of about 19 °C/66 °F. Temperatures in mountainous areas can plummet to 14-15 °C. It can even soar to the high 50 °F or higher during the winter months, and drop to freezing or lower in the nights. The Annamite Mountains in southern Laos get the highest average precipitation of more than 3000 mm (10 feet) per year. The average precipitation is highest in southern Laos, where the Annamite Mountains receive over 3000 mm (10 feet) annually. The annual rainfall in Vientiane is 1500-2000 mm (5 to almost 7 feet), and just 1000-1500 mm (3-5 feet) annually in the northern provinces.