The river flows in the western area of
Borneo island with predominantly
tropical rainforest climate (designated as
Af in the Köppen-Geiger climate classification). The annual average temperature in the area is 23 °C. The warmest month is May, when the average temperature is around 24 °C, and the coldest is December, at 22 °C. The average annual rainfall is 3726 mm. The wettest month is December, with an average of 495 mm rainfall, and the driest is August, with 160 mm rainfall. ==See also==