The Bila River is a river in northern Sumatra, Indonesia, about 1,200 km northwest of the capital Jakarta.

The river flows in southwest Java with predominantly tropical rainforest climate (designated as Af in the Köppen-Geiger climate classification).

The warmest month is August, when the average temperature is around 26 °C, and the coldest is January, at 23 °C.

[4] The average annual rainfall is 3766 mm.

The wettest month is November, with an average of 381 mm rainfall, and the driest is March, with 126 mm rainfall.