In the Genesis flood narrative, how long does rain fall while Noah is aboard the Ark?

In the Genesis flood narrative, rain falls for forty days and forty nights while Noah is aboard the Ark.

Genesis 7 describes the Flood beginning after Noah, his family, and the animals enter the Ark. The text says rain falls on the earth for forty days and forty nights, causing the waters to rise and cover the land. This number belongs specifically to the period of rainfall, not necessarily to the entire duration of the Flood.

A common mix-up is confusing forty days with the total time the waters remain high. Genesis also says that the waters prevail for 150 days before beginning to recede. Later, Noah waits through additional periods before the ground becomes dry and the occupants leave the Ark.

The number forty appears frequently in biblical narratives as a period of testing, transition, or preparation. In this story, it marks the intense phase of the catastrophe, while the wider chronology describes a much longer sequence of rising water, recession, and waiting.