Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The Bila River is a river in northern Sumatra, Indonesia, about 1,200 km northwest of the capital Jakarta. It is a tributary of the Barumun River.
Geography
The river flows in southwest Java with predominantly tropical rainforest climate (designated as Af in the Köppen-Geiger climate classification). The annual average temperature in the area is 24 °C. The warmest month is August, when the average temperature is around 26 °C, and the coldest is January, at 23 °C. 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.