When to book Thanksgiving and Christmas flights, and why holiday fares are different

The short answer: for Thanksgiving and Christmas, book earlier than you would for the same route at any other time of year, and don't count on a late drop. The usual advice about watching and waiting assumes demand that rises and falls. Holiday demand is booked into everyone's calendar months ahead, and airlines price it accordingly.

This year Thanksgiving is Thursday, November 26, and Christmas falls on a Friday. If you haven't booked yet, the most useful thing to know is where you still have room to move.

Why holiday fares behave differently

Airlines sell each flight in fare buckets: a few seats at the lowest advertised price, more at the next level up, and so on. On an ordinary Tuesday in February, the cheap buckets sell slowly and fares drift around for weeks. On the Wednesday before Thanksgiving, the same buckets fill early, because thousands of people need that exact day and nothing else will do.

That's why the general rules don't carry over. We explained in how far in advance to book that each route has its own point where fares start to climb. For peak holiday dates that point comes earlier, often much earlier, than for the same route in an ordinary month. And the last-minute deals people hope for are, as we wrote in do flight prices drop closer to departure, a reaction to flights that aren't selling. A holiday flight is the clearest case of one that is.

The days that cost the most, and the ones that don't

Not every day around a holiday is a peak day. The crush is concentrated:

• Thanksgiving: the Tuesday and Wednesday before, and the Sunday after. The Sunday after Thanksgiving has repeatedly been among the busiest days of the year at US airport security.
• Christmas: the last few days before Christmas, and the weekend after it as people head home or on to New Year's plans.

The days on either side are where the room is. Flying on Thanksgiving morning or Christmas Day itself is often far less in demand, because most people want to arrive before the holiday, not on it. Leaving a day or two earlier, or returning on the Monday or Tuesday after, usually means competing for seats with a lot fewer people.

That's also why a flexible window is worth more at the holidays than at any other time. Comparing one date against its neighbours is exactly what we described in what "shift two days and save" actually compares: the saving is the fare you could have had on a date you'd actually take, not a cherry-picked worst case.

Other ways to keep the cost down

• Check the nearby airport. A second airport in the same city can be a different market entirely on a peak day. It's worth comparing both before you book.
• Price two one-ways. On some routes, especially domestic ones, two one-way tickets on different airlines can beat a round trip. We covered when that works in round trip vs two one-ways.
• Count the bags. Holiday trips mean presents and winter clothes, and a basic economy fare plus two bag fees can cost more than a standard fare that includes one. See is basic economy actually cheaper.

Should you still watch the fare?

Yes, but watch it for a decision, not for a miracle. Watching tells you whether the fare in front of you is good for that route, that month and that booking window, so you can book with confidence instead of guessing. It won't conjure a cheap seat on the busiest day of the year.

We'll be straight about our own limits here. We judge a fare only against fares we've recorded ourselves for the same route, month and booking window. On many routes that history is still new, and for flights this holiday season a lot of them won't have enough of it to score a fare at all. When that happens we send nothing, rather than an alert built on guesswork. Here's why we'd rather stay quiet.

If you're flying this holiday season, book the peak days sooner rather than later, use the days around them, and if you're still deciding, watch the route — it's free while we're in beta. And if you're already thinking about next year's trip, that's the best time of all to start.