In Genesis’s account of Noah’s Ark, the floodwaters prevailed over the earth for 150 days. Genesis 7:24 states this after describing the rising waters and the destruction of life outside the Ark.
The 150-day figure is different from the 40 days and nights of rain mentioned earlier in the story. Genesis describes a longer period during which the waters remained dominant, followed by the Ark coming to rest and the waters gradually receding. These separate durations are often merged in simplified retellings.
The narrative uses several dated milestones to structure the Flood story, including the month and day when the Ark came to rest and when the ground finally became dry. Consequently, “150 days” refers to the period the waters prevailed, not the entire time Noah and his family remained aboard the Ark.