The river flows in the southeast area of Sumatra with predominantly tropical rainforest climate (designated as Af in the Köppen-Geiger climate classification).[3] The annual average temperature in the area is 26 °C. The warmest month is October, when the average temperature is around 28 °C, and the coldest is March, at 25 °C.[4] The average annual rainfall is 2932 mm. The wettest month is January, with an average of 433 mm rainfall, and the driest is September, with 63 mm rainfall.[5]
