If I’m flying for New Year’s, I try to book domestic flights by mid-November and international flights 4 to 10 months out. That’s the short answer. Wait too long, and holiday fares often climb fast – especially inside 21 days, when prices can jump by $100 to $200.

Here’s the simple version:

• Domestic trips: I book in late October to mid-November
• International trips: I start watching fares 4 to 10 months ahead
• Cheaper flight days: December 30, December 31, and January 1
• Most expensive return days: January 2 and January 3
• Best cutoff: If I’m within 6 weeks of departure, I stop waiting and book
• Late-booking tip: I check nearby airports, test one-way vs. roundtrip flights, and shift dates by a day or two

New Year’s travel costs more because most people fly on fixed dates. That pushes fares 40% to 80% above normal winter prices, and people who book in the better window save about 25% versus last-minute buyers.

If I miss the best window, I stop chasing the lowest fare and focus on the lowest fare still left.

New Year’s fares stay high for a simple reason: demand is squeezed into a small group of peak travel days, and most people can’t shift their plans much. When travelers are tied to fixed dates, airlines have little reason to roll out deep last-minute discounts.

Thanksgiving demand tends to spike and then cool off. New Year’s works differently. The travel period stretches into early January, so fares stay higher for longer. That’s why the best prices often show up earlier than many travelers expect.

The booking data shows that gap pretty clearly. Thanksgiving fares usually reach their low point around 35 days before departure, while Christmas and New Year’s fares tend to bottom out earlier, at about 51 days out. For New Year’s trips, booking sooner usually makes more sense.

September and October are usually the best months to watch prices and set alerts. For domestic New Year’s flights, the lowest fares most often show up in a booking window of 32 to 73 days before departure, with the statistical sweet spot around 51 days out.

By mid-November, that window starts to narrow. After that, prices tend to move in a pretty predictable way:

Airlines use dynamic pricing to push seats into higher fare classes as cheaper inventory sells out. On top of that, many lower-priced holiday fares come with advance purchase rules like AP7, AP14, or AP21. Once those cutoffs pass, those cheaper fare classes disappear. So the best window comes earlier, and the toughest prices usually hit in the final three weeks.

Once fares move into that top price band, the next section shows how to spot deals before the cheapest seats vanish.

If you’re within six weeks of departure, stop waiting and book. For international trips, book when the fare works for your budget.

If you haven’t booked yet, the next step is learning how to find cheap flights by setting alerts and moving fast when prices drop.