In the weeks leading up to Christmas, shoppers in Iceland spend a lot of their time browsing real and virtual bookstore shelves, searching for the perfect tomes to gift their friends and families. Then when all the paper comes off and books are unwrapped on Christmas Eve, everyone settles down with a warm drink to dive into their new books.

The tradition is called "jolabokaflod," or the Christmas Book Flood.

"The culture of giving books as presents is very deeply rooted in how families perceive Christmas as a holiday," Kristjan B. Jonasson, president of the Iceland Publishers Association, tells NPR. "Normally, we give the presents on the night of the 24th and people spend the night reading. In many ways, it's the backbone of the publishing sector here in Iceland."

Maybe it's because the weather isn't conducive to spending a ton of time outdoors, but the people in Iceland are generally big readers. According to a study conducted by Bifröst University in 2013, 50 percent of Icelanders read at least eight books per year, while 93 percent read at least one.

Iceland publishes more books per capita than any other country in the world except the U.K., according to the International Publishers Association 2015-2016 annual report. The Iceland publishing industry receives about 80 percent of its annual revenues in the two months or so leading up to Christmas reports Guide to Iceland.

The history of the Book Flood

The flood's tradition dates back to World War II, writes Hildur Knutsdottir in The Reykjavik Grapevine. Due to strict restrictions on currency, there wasn't a lot of imported giftware. Icelanders had money to spend and the restrictions on paper were more lenient, so books became the Christmas present of choice.

Long after the war, books stuck around during the holidays.

"This tradition stayed despite many flattering products that have arrived on the market in the past decades. The Clairol foot fixer, the Soda Stream-machine or even the iPad haven‘t managed to change the preference for the book as a good gift," writes Icelandic poet and novelist Gerður Kristný. "I have always been given books for Christmas. I remember vividly being an 11-year-old getting nine books that year! Looking at the pile I felt very grown up."

The tradition keeps reading alive and it thrills the writers who create the books, says Icelandic-born author, painter and broadcaster Hallgrímur Helgason.

"Thanks to the Jolabokaflod, books still matter in Iceland, they get read and talked about. Excitement fills the air. Every reading is crowded, every print-run is sold. Being a writer in Iceland you get rewarded all the time: People really do read our books, and they have opinions, they love them or they hate them. At the average Christmas party, people push politics and the Kardashians aside and discuss literature," Helgason writes.

"In Iceland book lives matter in every sense of that phrase: The shelf-life of the book, the lives in the book, the life of the writer and the life of the reader. God bless the Jolabokaflod."

How it works

A woman sips coffee outside of an Eymundsson store, the oldest and largest bookseller in Iceland. A woman sips coffee outside of an Eymundsson store, the oldest and largest bookseller in Iceland. (Photo: Helgi Halldórsson/flickr)

The flood starts with the November release of Bokatidindi (roughly translated into "Journal of Books"), a catalog of nearly every book published in Iceland.

"It is delivered to each and every home in the country, and for many it is a sign that Christmas is officially upon us," Knutsdottir writes. "And for Icelanders, Christmas is the time where you snuggle up and read your presents."

Once the catalog is released, Icelanders start shopping. Typically, people get at least one book for a Christmas gift and often they get many more. Presents are unwrapped on Christmas Eve, and that's when everyone curls up under blankets, often with a cup of warm chocolate or a non-alcohol ale seasonal ale called jolabland, reports jolabokaflod.org.

Flooding worldwide

As book lovers outside of Iceland began to hear about jolabokaflod, the idea began to spread. Publishers in the U.K. and the U.S. hopped on the bandwagon because well ... obviously they thought it was a good idea to sell a whole bunch of books in time for the holidays.

But word of giving books and reading books spread on social media too.

What will you be giving (or reading) on Dec. 24?

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.