The river flows in the southern area of Papua with predominantly tropical monsoon climate (designated as Am in the Köppen-Geiger climate classification).[4] The annual average temperature in the area is 22 °C. The warmest month is April, when the average temperature is around 24 °C, and the coldest is June, at 20 °C.[3] The average annual rainfall is 3072 mm. The wettest month is January, with an average of 464 mm rainfall, and the driest is July, with 28 mm rainfall.[5]