In the Book of Genesis, how many days and nights does the rain of Noah's Flood continue?

In the Book of Genesis, the rain of Noah's Flood continues for 40 days and 40 nights.

Genesis 7:12 gives this duration after Noah, his family, and the animals enter the ark. The text then describes the waters rising until even the mountains are covered. The 40-day period refers specifically to the rain, not to the entire time Noah and the animals remain aboard.

A common mix-up is treating 40 days as the total length of the Flood. Genesis gives several separate time markers: the waters prevail for 150 days, and Noah eventually leaves the ark after more than a year has passed since the Flood began. These figures belong to different stages of the story.

The number 40 also appears frequently in biblical narratives, including Moses' time on Mount Sinai and Israel's wilderness journey. In biblical storytelling, it is often associated with an extended period of testing or transformation.