Geography Bihar is mainly a vast stretch of very fertile flat land. It has several rivers: Ganga, Son, Bagmati, Kosi, Budhi Gandak, and Falgu to name a few. Central parts of Bihar have some small hills, for example the Rajgir hills.

The Himalayan mountains are to the north, in Nepal. To the south is the Chota Nagpur plateau, which was part of Bihar until 2000 but now is part of a separate state called Jharkhand.

Climate Bihar is mildly cold in the winter (the lowest temperatures being around 5 to 10 degrees Celsius). Winter months are December and January. It is hot in the summer (40 to 45 degrees Celsius). April, May and the first half of June are the hot months.

The monsoon months of June, July, August, and September see good rainfall. October, November, February, and March are very pleasant months for climate.