Here's When to Book Airline Tickets for the Cheapest Prices

Airfare doesn't care about your schedule: It ebbs and flows with the rhythms of the travel calendar. It's why airfare soars when the entire nation tries to cram into planes on the holidays and plummets when they're over. It creeps back up when schools go on summer vacation and falls again when kids head back to the classroom. It isn't a fixed price, but it's predictable if you watch the market long enough. We consulted with experts across the industry to find the best times to book and fly. Just give yourself plenty of time and be flexible.

One of the cheapest travel months ... sort of. The U.S. Bureau of Transportation Statistics notes that airline travel dropped to roughly 73.2 million passengers in January, around 6.6 million fewer than December, part of what SmarterTravel senior writer Ed Perkins calls "dark weeks" between New Year's Day and Martin Luther King Jr. Day. Airfare site Hopper found that the $212 average price of a round-trip domestic flight in January was not only 2.6 percent lower than in December, but 17 percent lower than the $257 forecast for June. But January may take a backseat to ...

The average round-trip domestic airfare ($224) was actually higher than January's, Hopper says, but the month also has the lowest average ticket prices for international travel from the United States, travel site Expedia says in a report using Airlines Reporting Corp. data. Why? Last year, just 14.7 million U.S. passengers booked international flights in February, down from 17 million in January and well below July's peak of 22.5 million. Domestic passenger counts also hit bottom, declining to 51.1 million from 54.1 million. But if you really want a domestic deal, you need to fly in...

Domestic economy tickets become cheapest, the Expedia report says. The $217 average round trip was 2.1 percent lower than the previous month, and dropped from more than $250 at summer's peak, thanks to school starting. Hopper data analyst Patrick Surry expects the same this year. The site initially predicted October ticket prices to be even lower, but a surge to 64.6 million passengers from 57.1 million -- thanks to people fleeing a potent hurricane season -- kept prices from bottoming out.

Rick Seaney, founder and CEO of travel pricing site FareCompare has said for years that the best time to book a ticket is at about 3 p.m. EST on a Tuesday, reasoning that many U.S. airlines post sales online late Monday or early Tuesday, inspiring price wars from competitors that settle by Tuesday afternoon. "But don't worry, you can find deals on other days if you know how to look," Seaney says. Like perhaps ...

With few exceptions, Expedia's report finds the lowest U.S. average prices, domestic and international, on Sunday. The premium paid for buying on the most expensive vs. cheapest day of week ranges from 15 to 120 percent for international flights, but a much more forgiving 8 to 27 percent for domestic flights. Thank corporate travelers; they are less likely to book business travel on weekends, when they aren't working.

The CheapAir 2018 Annual Airfare Study looked at 917 million airfares in more than 8,000 markets and found that the average fares by purchase day of week are all within $2 of one another. That's less than a 0.6 percent difference, which is negligible at best.

Just about all our sources agreed: Don't book a flight that leaves Sunday if you don't have to. Flying Wednesday instead of Sunday, for instance, saves an average $76, CheapAir says.

While they vary for booking, usually the best days to start or wrap up domestic travel, Seaney says. "Remember, we say 'usually' because this rule is not true for every single route," he says. "When shopping for tickets, always compare fares but also compare prices for different travel days -- a day or two earlier and later."

The lowest fares for domestic departure dates "vary wildly by origin," with the lowest average ticket prices found on flights departing Fridays -- expanding to Thursday or Friday departures for international flights, the Expedia report says. The price for getting that date wrong is far steeper on international flights (9 to 43 percent) than for those flying domestic (5 to 30 percent).

Dates for an airline fare sale may stretch from November to March, but dates of availability during that sale may not include coveted dates such as Thanksgiving, Christmas, and New Year's. Holidays, peak days, and some weekends are often exempted, though the available dates may still be a great deal. "Airlines will set aside a limited number of tickets at a sale price for each date and some dates will sell out at the lower prices before other dates do," says George Hobica, founder of AirfareWatchdog.

FareCompare's Seaney says it's tough to find a sweet spot for domestic travel deals, but this rule of thumb will get you a deal either way. Consider that 30-day threshold a moving target, though; peak summer travel and holidays can move the minimum booking time to two months. "Buy too early and you could pay too much," he says. "Buy too late and you could pay way too much."

Seaney advises giving even more time to international airfares, which have logistical issues that could alter price and availability. These are not tickets to leave until the last minute -- but keep your eyes open for a better bargain during that window. "If you can travel when you want and can fly when deals pop up, shop anytime," Seaney says. "You never know when an airline will unexpectedly drop prices."

The folks at travel site Skyscanner say their data supports booking a short-haul flight exactly seven weeks in advance. This varies a bit by destination, as flights to Chicago and New York benefit from a seven-week buffer, but are priced differently depending on the destination airport.

As you may have suspected, tightened airline capacity means last-minute deals are long gone, the Expedia report confirms. The "deep-slope, flat-tail model" of airline ticket pricing tends to hold airfares low for more than 100 days before departure, but starts climbing just before hitting that 30-day mark. It doesn't pay to procrastinate.

The best airfares are found an average 70 days in advance, but this 100-day span -- a broad range of days -- tends to feature fares within 5 percent of their lowest point, the CheapAir study finds. For better seat options (for an average $20 more) or to lock in a date, booking up to 168 days in advance works as well.

The peak months of June and July can be painful, but August and early September can offer deals. As a result, the prime booking window for summer travel ranges from just two weeks to 160 days, with $203 separating the best and worst prices of the season, CheapAir says.

The stretch between June 23 and Aug. 12 is the peak of summer travel and the most expensive time to fly. As an alternative, FareCompare's Anne McDermott suggests weekdays in April, early May, early June, or any time after Aug. 27.

It's fine to book summer travel between 3.5 months and two to four weeks before departure, and international travel between 5.5 months and four weeks before leaving, McDermott says. But discount airlines such as Frontier and Spirit don't raise fares until about two weeks before departure, while larger carriers including American and Delta raise fares about four weeks before.

Unless you're booking for Thanksgiving, travel options should be plentiful and inexpensive. Thanksgiving excluded, you can find great prices for 100 days to three weeks out, with the difference between the best and worst prices a relatively scant $83, CheapAir.com says.

Winter holidays make this a disaster, right? CheapAir.com reminds that there are periods between Thanksgiving and Christmas and between New Year's and Spring Break when very few people fly. As a result, the window for the best prices is between 21 and 110 days in advance -- though the difference between the best and worst tickets of the season is an ugly $230.

Spring Break ruins everything, mostly because it isn't just a college thing anymore. Now entire school districts shut down for a week and throw hordes of parents and kids into airports with everyone else. So you're out of luck if you book fewer than 46 days in advance -- but can find some of the best deals as early as three months out, CheapAir says. Book poorly and the range between the best and worst tickets is a punishing $263.

The best shot at a good airfare for Memorial Day (May 28 this year) is booking before May 7, Hopper says. The best round-trip deal averages $271, varying by destination, or $10 less than the same ticket for Easter weekend. "You know when you'll have time off, and when your folks are expecting you home … there's no excuse for not getting a good deal this year," Surry says.

Aside from the winter holidays, there is no holiday ticket more expensive. Even booking before June 13, you'll pay an average $314 for a deal, Hopper says, or about $70 more than to travel on Labor Day weekend, and only $10 less than a Christmas or New Year's ticket.

Labor Day (Sept. 3) is remarkably affordable for its place on the calendar, thanks largely to college kids leaving for school beforehand and younger kids going back to school immediately afterward. Hopper finds that booking by Aug. 13 brings a $245 average airfare -- the lowest of the summer and a better deal than even a President's Day fare ($247) in the dead of February.

No, Columbus Day (Oct. 8) isn't a day most folks have off, but it's a leaf-peeping milestone for which Hopper advises booking well in advance -- though also the cheapest holiday airfare at an average $225. Use the savings on a nice cabin with a view.

As Seaney says about the holidays, there are no good deals, just the "best bad deal." To get it, start thinking about it roughly a week before Halloween at the latest. Even that kind of planning will snag a $271 average airfare at best, and even that may require some flexible scheduling, Hopper says.

The "best bad deal" theory applies here as well. You aren't getting a deal; if you're lucky, you're getting a seat. Hopper says even that's at risk if not booking before Halloween. Afterward, prices only rise from an average $324.

The airline industry has caught on to the "late Christmas" ploy. The only benefit to moving holiday travel to New Year's Day is the extra week to mull it over. Don't decide until after Nov. 5, however, and Hopper says the $324 average won't be waiting for you.

AirfareWatchdog's Hobica doesn't think much of these dates, finding them either arbitrary or based on incomplete data. His preferred method for finding cheap fares involves signing up for alerts from either travel sites such as his -- or the airlines themselves -- or following fare activity on Twitter and other social media and nailing down the right price when it comes along. There's no specific date and "no magic formula" for the best price, Hobica says, just a lot of work and a little luck.

Even CheapAir's exhaustive study reaches a conclusion no traveler will like: Airfare shopping is no place for FOMO. You can't fear missing out on the best deal, because it's going to happen. The site's survey found that the lowest fare for any one trip changed an average 62 times during the period it was sold, or once every five to six days. It didn't fall or rise by just a little, either: Each change was an increase or drop of $36, on average. "We hear from travelers all the time who are frustrated that a fare they saw one day is dramatically higher the next," said Jeff Klee, CEO of CheapAir. "It's equally disturbing when you book a trip and find out two weeks later that the price has gone way down."