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 25 °C. The warmest month is September, when the average temperature is around 27 °C, and the coldest is February, at 24 °C.[4] The average annual rainfall is 3176 mm. The wettest month is December, with an average of 501 mm rainfall, and the driest is September, with 33 mm rainfall.[5]
