What are the White Nile and the Blue Nile?

The Nile River is composed of two primary tributaries, the White Nile and the Blue Nile, which converge at Khartoum, Sudan, to form the main river.12

The White Nile

The White Nile is the longer of the two tributaries. It begins at Lake Victoria and flows north through Uganda and South Sudan. This section of the river is characterized as a wide, placid stream that often flows through swampy regions. It provides a consistent, year-round supply of water, contributing more than 80 percent of the total volume of the Nile during the dry season (April–May).123

The Blue Nile

The Blue Nile originates near Lake Tana in the Ethiopian highlands. It is a more seasonal river, experiencing a pronounced flood season from late July to October due to monsoon rains in Ethiopia. The Blue Nile is the primary source of the Nile's floodwaters, accounting for nearly 70 percent of the total inflow into Lake Nasser during the flood period.142