SBR- Content.pmd - INBO

3 - Water in the Mekong BasinWater in the 3Mekong Basin1. ClimateThe Mekong basin encompasses a range of climates, from tropical to cool temperate. Some of thehigher peaks in the Tibetan Plateau are permanently snow-capped, and much of this part of the basinis under snow in winter. Downstream dry season flows are maintained partly by snowmelt. As thealtitude of the river drops through Yunnan Province in the People’s Republic of China, the climatebecomes warmer and precipitation increases, with some areas experiencing 1,700 mm of annualrainfall, mainly between May and October. 1The Mekong begins on the Tibetan Plateau at analtitude of nearly 5000 metresIn the Lower Mekong Basin, maximumtemperatures are encountered in the inland areasof Lao PDR, Thailand and Cambodia in Marchand April. Depending on the location andaltitude, temperatures range from 30°C up to38°C . Coolest temperatures occur betweenNovember and February, with the lowesttemperatures at high elevations. Average dailyminimum temperatures are often below 20°Cand as low as 15°C in parts of Lao PDR. Duringthe rainy season, between June and October,temperatures are usually in the range 25-30°C,with relative humidities between 80-95 percent.The delta and coastal areas are subject to marineinfluences. Between November and February,the Northeast Monsoon brings coolertemperatures, while the wet season is a productof the Southwest Monsoon between June andSeptember.13