In Genesis, how many days and nights did rain fall before the Flood waters rose?

In Genesis, rain fell on the earth for forty days and forty nights during the Flood.

Genesis 7:12 uses this memorable period to describe the rainfall after Noah, his family, and the animals entered the Ark. The same chapter also says that the waters prevailed on the earth for 150 days, a separate duration that is often confused with the forty days of rain.

The flood narrative includes several time markers: Noah was told to enter the Ark seven days before the rain began, the rain continued for forty days and nights, and the waters later receded over an extended period. The number forty is also prominent elsewhere in biblical literature, including Moses’ periods on Mount Sinai and Israel’s years in the wilderness. In the Flood story, however, the specific answer concerns rainfall, not the total time that the Ark remained afloat.