Why holiday travelers should book trips this week

For those looking to score flight deals, it's already holiday travel season. The travelers who get the best airfares will be those who searched the smartest, not the longest.

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

Both Hopper, an airfare prediction app, and Hipmunk, an online travel company, say holiday airfare should be booked before Halloween.

Travelers who book flights this week could save up to 27% on Thanksgiving travel and up to 38% on Christmas trips, Hipmunk reports. Hopper's data shows the same trend highlighting dramatic increase on domestic flight this Thanksgiving - $325 on average, compared with $288 from last year.

"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 booking your travel, don't forget to factor in airline baggage fees. Your cheaper flight may not save you much once you add in the price of bags.

You'll also want to consider additional related costs, like travel insurance, snacks or selecting premium seats.

If you want to avoid the crazy airport crowds, Hipmunk suggests traveling on Thanksgiving or Christmas Day, when bookings are at a minimum.