What was the biblical duration of the rain during Noah’s Flood?

The biblical duration of the rain during Noah’s Flood was 40 days and 40 nights.

Genesis 7:12 states that rain fell upon the earth for forty days and forty nights. Genesis also gives other time periods connected with the Flood, including the total time the waters prevailed and the period Noah waited before leaving the Ark.

Those additional numbers can create confusion. The forty-day figure specifically describes the continuous rainfall in the opening stage of the Flood narrative; it does not mean that the entire episode ended after forty days. Genesis says the waters later remained on the earth and gradually receded.

The number forty is also familiar from other biblical narratives, including Moses’ time on Mount Sinai and Israel’s wilderness journey. In the Ark story, however, the phrase refers directly to the rainfall.