The river flows in the northern area of Papua with predominantly tropical rainforest climate (designated as Af in the Köppen-Geiger climate classification).[2] The annual average temperature in the area is 22 °C. The warmest month is October, when the average temperature is around 23 °C, and the coldest is March, at 21 °C.[3] The average annual rainfall is 4269 mm. The wettest month is April, with an average of 487 mm rainfall, and the driest is July, with 278 mm rainfall.[4]