Why holiday travelers should book airfares this week

— -- It's beginning to look a lot like the holiday travel season — at least for those looking to score flight deals.

Airfare booking and tracking sites indicate this week may be the least expensive period to book those costly holiday travel flights.

Hopper, an airfare prediction app, and Hipmunk, an online travel company, agree that holiday airfare should be booked before Halloween. Hopper's data show a dramatic increase on domestic flight this Thanksgiving — $325 on average, compared with $288.

Hipmunk's data looks at holiday season price histories and found that the best time to book a flight is this week. The company estimates those who book now will save an estimated 27 percent on flights, compared with those who wait until the last minute.

Hopper's data concur: It estimates prices will rise $10 per day for those who wait until November to buy.

"The busiest and most expensive day to depart is Wednesday, Nov. 22. You can save $54 by departing on Thanksgiving morning, or you can save $48 by departing on Monday, Nov. 20," according to the company's holiday travel index. "The busiest and most expensive day to return is Sunday, Nov. 26. You can save $161 by returning on Wednesday, Nov. 29, instead."

When it comes to Christmas, it pays to book in early October. Hipmunk estimates that 84 percent of Christmas flight bookings are made in early October. That means consumers will want to book early to get not only low prices but also their choice of schedules and seat assignments.