The river flows in the southern area of Papua with predominantly tropical rainforest climate (designated as Af in the Köppen-Geiger climate classification).[5] The annual average temperature in the area is 22 °C. The warmest month is January, when the average temperature is around 24 °C, and the coldest is June, at 20 °C.[6] The average annual rainfall is 5547 mm. The wettest month is May, with an average of 594 mm rainfall, and the driest is July, with 384 mm rainfall.[7]