The river flows in South Papua with a predominantly tropical rainforest climate. The annual averagetemperature in the area is 22 °C. The warmestmonth is February when the average temperature is around 24 °C, and the coldest is June, at 20 °C. The average annual rainfall is 3143 mm. The wettest month is February, with an average of 403 mm rainfall, and the driest is July, with 66 mm rainfall. The average rainfall for the whole catchment area between 2002 and 2011 was 3577 mm.