In Genesis, the Floodwaters prevailed on the earth for 150 days.
This figure comes from Genesis 7:24, which says that the waters prevailed for 150 days. The statement describes the period during which the waters remained dominant after the Flood began, rather than the 40 days and 40 nights of rainfall. Genesis later says that the waters began to decrease and that the ark came to rest on the mountains of Ararat.
The chronology contains several separate intervals, which can cause confusion. Rain fell for 40 days and 40 nights, the waters prevailed for 150 days, and Noah’s family remained in the ark until God instructed them to leave. These figures are not interchangeable descriptions of one event.
The Flood narrative uses dated milestones, including Noah’s age and calendar dates for the waters rising and receding. Readers comparing translations may notice differences in wording, but the 150-day statement is a clear numerical detail in Genesis 7.