The story of Noah and the Ark is one of the most popular and beloved tales of Western culture. While Noah's story originated in the Bible and remains best understood in the context of God's Word, it has also become an archetype of modern society -- one that represents both judgment and salvation in different degrees.

The power of Noah's Ark as a cultural icon can best be seen through Hollywood's fascination with tale -- including movies such as Evan Almighty and Daren Aronofsky's Noah.

Unfortunately, there are a number of misconceptions and mysteries surrounding the biblical account of Noah and the Ark. For example, people often have interesting (and perhaps overblown) ideas regarding the "sons of God" and Nephilim described at the beginning of Genesis 6. In addition, scholars and laypeople alike actively disagree on the extent of the flood itself -- was it a worldwide phenomenon, or simply a regional event that affected the "known world" of the original audience?

These are good questions that deserve to be addressed. They deserve to be answered as well, whenever such answers are possible.

With that in mind, let's gain some clarification on another question that often puzzles people familiar with Noah's story. Namely, how long was the flood? The short answer to that question is 1 year and 10 days. If you want the longer explanation -- keep reading.

The Text

The beginning of the flood narrative is relatively simple and straightforward:

¹¹ Now the earth was corrupt in God’s sight and was full of violence. ¹² God saw how corrupt the earth had become, for all the people on earth had corrupted their ways. ¹³ So God said to Noah, “I am going to put an end to all people, for the earth is filled with violence because of them. I am surely going to destroy both them and the earth. ¹⁴ So make yourself an ark of cypress wood; make rooms in it and coat it with pitch inside and out.
Genesis 6:11-14

Likewise, God's basic instructions regarding the ark and the coming judgment for the world are not difficult to follow:

The Lord then said to Noah, “Go into the ark, you and your whole family, because I have found you righteous in this generation. ² Take with you seven pairs of every kind of clean animal, a male and its mate, and one pair of every kind of unclean animal, a male and its mate, ³ and also seven pairs of every kind of bird, male and female, to keep their various kinds alive throughout the earth. ⁴ Seven days from now I will send rain on the earth for forty days and forty nights, and I will wipe from the face of the earth every living creature I have made.”

⁵ And Noah did all that the Lord commanded him.
Genesis 7:1-5

When the water hits the fan, however, the timing of events becomes more difficult to follow. Fortunately, the biblical text gives us several markers to help us keep track of what's going on -- and for how long.

For example, we are given a definitive start date for the flood itself:

¹¹ In the six hundredth year of Noah’s life, on the seventeenth day of the second month—on that day all the springs of the great deep burst forth, and the floodgates of the heavens were opened. ¹² And rain fell on the earth forty days and forty nights.
Genesis 7:11-12

After that, it's all a matter of counting the numbers.

The Timeline

Here's the first mention of timing we're given during the actual flood event:

¹⁷ For forty days the flood kept coming on the earth, and as the waters increased they lifted the ark high above the earth. ¹⁸ The waters rose and increased greatly on the earth, and the ark floated on the surface of the water.
Genesis 7:17-18

So, we know that the actual period of water flooding across the earth was 40 days. That's the first notch on our stopwatch.

Then comes verse 24:

²⁴ The waters flooded the earth for a hundred and fifty days.
Genesis 7:24

Now we have 40 days of active flooding, plus an additional 150 days of water remaining on the earth in an elevated state. That's a total of 190 days. 

We get more numbers at the beginning of chapter 8, which is where things get a little more complicated:

² Now the springs of the deep and the floodgates of the heavens had been closed, and the rain had stopped falling from the sky. ³ The water receded steadily from the earth. At the end of the hundred and fifty days the water had gone down, ⁴ and on the seventeenth day of the seventh month the ark came to rest on the mountains of Ararat. ⁵ The waters continued to recede until the tenth month, and on the first day of the tenth month the tops of the mountains became visible.
Genesis 8:2-5

Still following? We started on the 17th day of the second month, and now we're up to the 17th day of the seventh month. So, at this point Noah and his family have been in the ark for five months.

It keeps going:

⁶ After forty days Noah opened a window he had made in the ark ⁷ and sent out a raven, and it kept flying back and forth until the water had dried up from the earth. ⁸ Then he sent out a dove to see if the water had receded from the surface of the ground. ⁹ But the dove could find nowhere to perch because there was water over all the surface of the earth; so it returned to Noah in the ark. He reached out his hand and took the dove and brought it back to himself in the ark. ¹⁰ He waited seven more days and again sent out the dove from the ark. ¹¹ When the dove returned to him in the evening, there in its beak was a freshly plucked olive leaf! Then Noah knew that the water had receded from the earth. ¹² He waited seven more days and sent the dove out again, but this time it did not return to him.
Genesis 8:6-12

Then, finally, we are given an end date:

¹³ By the first day of the first month of Noah’s six hundred and first year, the water had dried up from the earth. Noah then removed the covering from the ark and saw that the surface of the ground was dry. ¹⁴ By the twenty-seventh day of the second month the earth was completely dry.

¹⁵ Then God said to Noah, ¹⁶ “Come out of the ark, you and your wife and your sons and their wives.
Genesis 8:13-15

There it is. Noah entered the ark when he was 600 years old -- specifically on the 17th day of the second month. He stepped off the ark exactly 1 year and 10 days later.