<P> The flooding of the Nile (Arabic: عيد وفاء النيل ‎, translit . eid wafa al - nayl) has been an important natural cycle in Egypt since ancient times . It is celebrated by Egyptians as an annual holiday for two weeks starting August 15, known as Wafaa El - Nil . It is also celebrated in the Coptic Church by ceremonially throwing a martyr's relic into the river, hence the name, The Martyr's Finger (Coptic: ⲡⲓⲧⲏⲃ ⲛⲙⲁⲣⲧⲏⲣⲟⲥ, Arabic: Esba ` al - shahīd ‎). Ancient Egyptians believed that the Nile flooded every year because of Isis's tears of sorrow for her dead husband, Osiris . </P> <Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (August 2017) (Learn how and when to remove this template message) </Td> </Tr> </Table>

When does the nile river flood every year