Does It Matter Which Day I Fly?

Yes, this one you’ll want to think about carefully, and also ask yourself: How flexible is my holiday travel?

“If you have flexibility, in general it will pay to extend your trip,” Mr. Surry said.

Regarding Thanksgiving, the most expensive day to depart is the Wednesday before, which should not come as a surprise as it’s also one of the busiest travel days of the year. But if you are able to leave on the Monday or the Thursday of that week you can save around $50 on the first leg of your trip. The same goes for your return day. The busiest and most expensive day to come back is Sunday. But you can save around $160 by returning on Wednesday, Nov. 29, instead, Mr. Surry said.

For Christmas this year, the cheapest days to depart are Saturday, Dec. 16, or Tuesday, Dec. 19, which can save you about $110 compared to traveling on the busiest day, which is Friday, Dec. 22. The most popular return day is New Year’s Day, and returning on Thursday, Jan. 4, instead could save you around $100, according to Hopper’s data.

Does It Matter Where I’m Going?

Yes, data for domestic flights show that some destination cities are more expensive to travel to than others, which can be tied to demand.

Priceline.com found that the most popular travel route for both Thanksgiving and Christmas is New York City to Florida (Miami, Fort Lauderdale and Orlando). For Christmas travel, these destination cities are also among the ones with the highest “holiday premium,” as Hopper terms it, meaning the greatest increase in price compared to non-holiday travel.

No matter where you are traveling from for the Christmas holiday, you can expect to pay up to 82 percent more for a fare to Miami ($383 instead of $211), according to Hopper. Fort Lauderdale and Orlando see spikes of over 60 percent.

For Thanksgiving, you can expect to spend 40 percent more than usual for trips to Denver and Boston.