Geography Bihar is mainly a vast stretch of very fertile flat land. It has several major rivers: Ganga, Son, Bagmati, Kosi, Budhi Gandak, Chandan, Orhani and Falgu. 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.
Bihar is mildly cold in the winter (the lowest temperatures being around 5 to 10 degrees Celsius; 41 to 50 degrees Fahrenheit). Winter months are December and January. It is hot in the summer(with average highs around 35-40 Celsius; 95-105 Fahrenheit). April to mid June are the hot months. The monsoon months of June, July, August, and September see good rainfall. October & November and February & March have pleasant climate.