The river flows in the northern area of Sulawesi island with predominantly tropical rainforest climate (designated as Af in the Köppen-Geiger climate classification).[3] The annual average temperature in the area is 23 °C. The warmest month is October, when the average temperature is around 26 °C, and the coldest is February, at 21 °C.[4] The average annual rainfall is 2133 mm. The wettest month is July, with an average of 270 mm rainfall, and the driest is September, with 53 mm rainfall.[5]
