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 22 °C. The warmest month is August, when the average temperature is around 24 °C, and the coldest is September, at 20 °C.[4] The average annual rainfall is 5543 mm. The wettest month is April, with an average of 550 mm rainfall, and the driest is January, with 263 mm rainfall.[5]