Genesis 7:6, 11-12, 24

Noah was 600 years old when the flood covered the earth.

When Noah was 600 years old, on the seventeenth day of the second month, all the underground waters erupted from the earth, and the rain fell in mighty torrents from the sky. The rain continued to fall for forty days and forty nights.

And the floodwaters covered the earth for 150 days.