For how many days and nights did rain fall in the Genesis flood account?

In the Genesis flood account, rain fell for 40 days and 40 nights. Genesis 7:12 uses this phrase to describe the rainfall that covered the earth in the narrative.

The 40-day period is not the same as the total duration of the Flood. Genesis separately says that the waters prevailed on the earth for 150 days, and it provides later dates for the waters receding and the Ark coming to rest. These passages describe different stages of the story rather than competing versions of one duration.

Forty is a recurring biblical number in other narratives, including Moses’ time on Mount Sinai and Israel’s wilderness journey. In Noah’s story, however, the specific phrase refers to the period of rain. Retellings sometimes incorrectly use 40 days as the entire time Noah and the animals remained aboard the Ark.