The river flows in the northern area of Papua with predominantly tropical rainforest climate (designated as Af in the Köppen-Geiger climate classification).[3] The annual average temperature in the area is 21 °C. The warmest month is October, when the average temperature is around 22 °C, and the coldest is January, at 18 °C.[4] The average annual rainfall is 5121 mm. The wettest month is March, with an average of 573 mm rainfall, and the driest is July, with 324 mm rainfall.[5]