According to Genesis, how long did Noah’s rain last during the Flood?

According to Genesis, Noah’s rain lasted 40 days and 40 nights.

Genesis 7 describes rain falling continuously for this period after Noah, his family, and the animals entered the Ark. The text separately says that the floodwaters prevailed for much longer, so the period of rainfall should not be confused with the total duration of the Flood.

The number 40 has recurring importance in biblical narratives. Other examples include Moses’ 40 days on Mount Sinai and Israel’s 40 years in the wilderness. In the Genesis account, the rain begins after Noah is told to enter the Ark, and the waters rise high enough to cover the mountains.

A common mix-up is to answer 40 days for every Flood-related time span. Genesis also mentions seven days before the waters arrive, 150 days during which the waters prevail, and a much longer overall sequence before Noah leaves the Ark.