Genesis says the Flood waters prevailed over the Earth for 150 days.
Genesis 7:24 states that the waters prevailed upon the Earth for 150 days. This figure belongs to the broader chronology of the flood and is different from the 40 days and 40 nights during which rain fell. The narrative describes the waters rising, covering the mountains, and later beginning to recede.
The two numbers are often blended together because both occur in the same account. Genesis presents them as separate stages: rain falls for 40 days and 40 nights, while the waters remain dominant for a longer period. The text also includes additional dates and waiting periods, making the complete chronology more detailed than either number alone.
Flood narratives from other ancient cultures use their own durations and sequences. Even within Genesis, interpretations of the calendar details can vary, but the verse’s direct statement is stable: the waters prevailed for 150 days. That makes the number a clear textual fact rather than a modern estimate.