In Genesis, the Flood waters prevailed over the earth for 150 days in Noah’s Ark story.
Genesis 7:24 states that the waters prevailed for 150 days after describing their rise over the land. This is a different measurement from the 40 days and 40 nights of rain. The rain marks the period of precipitation, while the 150-day figure describes how long the waters continued to dominate.
Genesis then says that God remembered Noah and caused a wind to pass over the earth. The fountains of the deep and the windows of heaven were closed, and the waters began to recede.
Because the narrative uses several durations, summaries can accidentally treat them as interchangeable. The 150 days should therefore be identified specifically as the period during which the waters prevailed, not as the total duration of rain or the entire time Noah stayed in the Ark.