Flights are cheapest 5 to 16 weeks out in 2018: Here’s when to book
Trying to find the absolute cheapest airfare for a trip you are planning is like playing a game that feels too easy to lose. Now in this era of ‘big data' where many companies are able to check airfares on every route every day to calculate the cheapest possible time to buy, it's finally a bit easier.
Only a few years ago the advice was often to buy between 4 and 6 weeks out, but things have changed and it really depends on where you are going. As you'll see in the 2018 update below, the window for buying the cheapest fares starts earlier these days and buying about 4 months out often leads to the best deals. We've summarized a variety of studies below and with a quick scan you should be able to get some insight on when to buy and when to wait.
Note: This article was first published in 2012, and has been updated and revised each year as new information has come out, most recently in February, 2018.
2018 UPDATE: The data for 2017 has been consistent, but still complicated
Several different companies are now examining millions of airline ticket prices and crunching the numbers to help tell us when the optimal time to buy is. In the past the patterns were easier to summarize, but now there is more variance from one region to another, so you have to check the information below for whatever kind of flight you are considering purchasing.
For the tests we ran below we used the very helpful tool from Cheapair.com.
Summary: Buying air tickets earlier will usually save you money
In years past the sweet spot for buying cheap tickets often didn't start until 6 to 8 weeks before the flight, but the data from 2017 shows once again that the cheaper airfares are now usually available starting 4 to 6 months out in many cases. In other words, if you are sure you want to fly on particular dates, you can usually get something close to the lowest possible fare if you book almost half a year out.
Another interesting thing about the data is that once you reach the beginning of that “sweet spot” where fares are near their low for any given flight, they still bounce around by up to US$50 over the next couple of months before they start heading higher as the flight approaches. So the best strategy is to set an alert for fare decreases on the route that you are shopping for, and buy as soon as you get one of those dips.
North America to Europe: 7 to 16 weeks out is usually the sweet spot
The optimal purchase window varies a bit depending on your departure and arrival cities, but generally speaking if you are flying between North America and Europe then the fares will be close to their lowest about 16 weeks out and you usually (but not always) don't have to worry about them shooting up until about 7 weeks out.
As long as you are within that 16 week window, the longer you wait the greater the chance that the fares will start jumping up for good. This is especially true for popular travel periods such as July and August. In spring and autumn you can usually get away with waiting a bit longer.
North America to the Caribbean: Book 3 to 12 weeks out
The great news is that if you want to go to a Caribbean hot spot such as Cancun, San Juan, or Nassau, you can often get the lowest fares only 2 or 3 weeks out. You can book as early as 10 to 12 weeks out and lock in the best fares, but they usually don't go any lower than that so waiting longer isn't really advisable if you are sure when you want to go.
The Caribbean hurricanes in 2017 won't change anything, in case you were curious. The islands that were affected most are all small islands that only got a small percentage of Caribbean flights in the first place. The busy airports such as Cancun, Punta Cana, and even San Juan (which has mostly recovered) should carry on the same as before when it comes to airfare windows.
North America to Asia/Pacific: 8 to 20 weeks is cheapest
As of 2016 it was necessary to book long flights between North America and Asia almost half a year in advance for the lowest fares, but in 2017 and into 2018 it seems that you can book between about 8 and 20 weeks to get something close to the lowest possible price on any flight. Generally speaking, the longer the flight the earlier that people book it, so it's wise to book as soon as you are sure of your dates.
The good news is that you no longer have to book so far in advance to get something close to the lowest fare. The more obscure your destination (Hanoi, Kathmandu etc), the earlier you should probably book. For more common destinations such as Tokyo, Singapore, and Bangkok, you have more time to wait.
North America to Middle East & Africa: 6 to 12 weeks is best
Another case where flight shoppers in 2018 can wait a bit longer to get a great deal than even a year ago, you should now be able to get a good fare to a place like Dubai, Abu Dhabi, or Cairo only 6 weeks or so out.
North America to South America: 5 to 16 weeks is cheapest
In 2018 there is a wider range for the lowest fares going from North America to South America. Many of these are not especially popular routes so there isn't much competition on them. In cases like this it's usually best to book early because if there is only one airline flying that route, you are vulnerable to a nasty surprise.
On short and popular routes, 3 to 4 weeks is usually fine
If you are flying on a very popular route, and especially a shorter one such as Los Angeles to Las Vegas or San Francisco, or New York to Washington DC, the window with the lowest fares is usually between 2 or 3 weeks and 8 weeks or so. Since so many people book these kinds of flights with little notice, you can usually get a very low fare even 3 weeks out.
Flights within Europe: Buy as early as possible
In reality the cheapest fares within Europe are almost all on the low-cost carriers such as Easyjet and RyanAir. If you are flying on any of those airlines, the fares ALWAYS start out cheap and get more expensive as more seats are sold. So the cheapest time to buy on a low-cost airline is NOW (or as soon as tickets go on sale, which is usually 11 months out).
Flying on a low-cost carrier (even to Europe): Buy now
As mentioned just above, if you are flying on one of the low-cost airlines, the seats go on sale about 11 months out at the lowest price, and they keep getting more expensive as each next group of seats are sold.
This is even true on Norwegian Airlines between the US and Europe. They offer the lowest fares in general on scores of popular routes, so if you are sure of your dates you should buy the tickets as soon as possible to lock in the lowest fare. They won't be getting any cheaper.
Cheapest times of the year to fly
The trends above should be valid for flights for most of 2018 and into 2019, but there are a few times of the year that are always a bit cheaper than others. For this information we look to research from Rick Seaney of FareCompare, who has been doing this longer than anyone else.
Domestic US flights are cheapest
January 7 to March 5 (between Christmas Break and Spring Break)
April 18 to June 2 (between Spring Break and Summer travel season)
August 22 to mid December (most summer trips end and autumn is a slower season)
If you can fly in any of the periods mentioned above you are likely to get lower fares than if you fly during the traditionally busier periods.
US to Europe flights are cheapest
Before June and after mid August (summer season is by far the busiest, and it ends earlier than you might think)
Weekdays and especially Tuesdays and Wednesdays (Even more so than domestic travel, trans-Atlantic travelers like to travel Fridays through Sundays, so flying the other days will almost always be cheaper).
Cheapest time to book flights for Christmas and New Year's trips
According to a 2015 study by Skyscanner, the absolute cheapest time to book flights for the popular dates just before Christmas and New Years is August 10 to 16, at least based on their 2014 data. The study also shows that fares only inch up a bit in later August and into September, but that by early November the fares will be closer to their peak.
Previously we'd heard that it's best to buy holiday flights as early as possible, which is usually 11 months out for most airlines. I think that's still mostly true, partly because it will allow you to pick the best possible departure times in both directions. But if you aren't quite so picky as to which time of day you leave and return, waiting until mid August seems like a decent idea and you'll still get a relatively good fare.
Important exception: Book flights on low-cost airlines as early as possible, always
If you are thinking about booking a flight on a low-cost airline, such as Southwest or Spirit in the US, or EasyJet or Ryanair in Europe, or Air Asia in Asia, the cheapest fare will always be as early as you are ready to commit. Unlike the more traditional airlines, the low-cost carrier revenue model is based on starting with all seats as cheap as they'll ever be when the flight is officially in the system. Then as seats are sold on that flight, the fare goes up as the plane is selling out. So maybe the first 20% of the seats are sold at the lowest price, and when those are gone, the next 20% are sold at a higher price, and so forth until all seats are sold or the plane takes off.
However, it's important to consider the fact that “low-cost airlines” aren't necessarily cheaper than their more traditional counterparts. Specifically, Southwest Airlines will often be more expensive than American or United, at least once the first group of cheap seats is gone. Also, since traditional airlines do in fact lower fares during the sweet spot of a few weeks to a few months before departure, you might find that waiting for those lower fares might be the best deal of all.
Airfares are still often cheapest on Tuesday, in spite of a recent report saying otherwise
In late 2014 there was another airfare report that seemed to bust the “myth” that fares were often lowest on Tuesdays. The problem is, the report is very misleading and fares are still probably lowest on Tuesdays (or Mondays or Wednesdays). The report only looked at the prices paid on each day of the week, rather than the fares offered each day of the week.
It's well known that many leisure travelers book on Saturdays, which is one reason why many fare sales are expired by then. But it's also true that a huge majority of full-fare business travel is booked Mondays through Fridays. For this reason, it can appear that fares are higher during the week and lower on weekends even though the opposite is true. In other words, if I buy a US$300 roundtrip from LA to NYC on Saturday and some business traveler's assistant buys the seat next to me for US$800 (fully refundable) on Tuesday, the study makes it look like fares offered are actually higher on Tuesdays.
The advice: Check any and every day of the week, and if it's the weekend you might want to wait a few more days to see if fares drop.
Why do airfares go up and down and up again as the day approaches?
Looking at the data above, you might think the airlines are playing some sort of game with fliers, but these pricing policies are actually a result of elaborate data and computer models that help them make the most money from each plane that leaves the ground. Here's why:
People who buy plane tickets early are less price sensitive
In the world of economics they call this being “inelastic” in that in some situations consumers will buy almost exactly as many tickets, even if the price is higher. Airlines (obviously) want to maximize their profit for every seat they sell on the plane, so they take advantage of those who are driven to lock in early.
Consumers who buy early might:
- Already have set vacation days they want to use all of
- Be attending an event, such as a wedding, where there's no flexibility
- Be someone who feels great stress until the ticket is locked in
In the above situations, whether a round-trip between Los Angeles and London is US$800 or US$1100, the person buying at least 3 months out is likely to buy either way. There is little incentive to airlines to sell a ticket for $800 if they'd sell almost as many at $1100.
People who buy plane tickets late are also less price sensitive
Similarly, consumers who are interested in flying 10 or fewer days from any given moment are also inelastic. They are likely to pay a premium for the convenience of going soon, so there's little incentive for airlines to discount these tickets either.
Consumers who buy at the last minute might:
- Have just gotten approval for fixed time off soon
- Have an event on a fixed date (a football game, etc)
- Be someone who hates to commit to things early, and is willing to pay extra for the added flexibility
Now, keep in mind, that anyone who is hoping to fly in 10 days or fewer from now will see higher prices, and they'll have the option of going 2 or 3 weeks later to save quite a bit of money. This price discrimination allows airlines to sell more expensive seats to those who can't wait, and cheaper tickets to those who can.
What happened to cheap “last-minute” fares?
In reality, it's always been difficult to find last-minute airfare bargains, at least to specific places you already want to visit. There are still examples of those weekly fare sales where an airline publishes a list of last minute bargain flights, but anyone who's paid attention to them can see the problem.
They tend to offer cheap flights between obscure city pairs on the least popular travel dates. So if you are ready to fly between, say, Charlotte and Bermuda this coming Saturday and return the following Tuesday, those last-minute deals could be for you. But for most of us, they never appear for places we really want to go and at times we want to travel.
Why no last-minute deals, you might ask? Why are airlines willing to fly with empty seats instead of filling them for low prices?
The reason airlines don't lower prices for unsold seats at the last minute is that the last thing they want to do is condition travelers to wait until the last minute, hoping for a bargain, and then sometimes not flying at all when a bargain doesn't appear.
Think about it. If you wanted to go from Los Angeles to London at some point soon, and a round-trip next month is $900, but if you go in 2 days it's only $650, you are likely to buy the cheap ticket two days from now, or skip it and hope that the same deal is available next month when you are ready to go.
Airlines make more money on each plane-load of people if they condition passengers into buying earlier at higher prices, or very early at even higher prices.
When to wait for fare sales
This all ties in with the economic principles above. You'll notice fare sales by various airlines, and they usually appear in the middle of a season (summer, for example) trying to fill up seats for the rest of that season. In some cases they'll announce an autumn fare sale in August, but it always tends to be for times of the year when the fewest people travel, namely, January through March plus October and November.
If you are waiting for a fare sale and wondering when it might appear, it's important to consider the airlines' motivation in announcing them. Let's say they announced an October fare sale in June, with round-trip fares way lower than those offered in summer. That would actually cannibalize their business for July through September. If someone is considering paying a high fare to fly in August, the airlines are not motivated to show them a much lower fare if they waited. That would lead to empty seats in late summer, which would be very costly for them.
In almost all cases you are best off waiting until 6 weeks or so before your departure date, but it's also important to track the fares before that, and keep an eye on fare sales.
This same research by the AP also said that fare sales usually appear on Tuesdays and are over by the end of Thursday, so check fares early in the week and if a price drops then jump on it. They also found the highest fares showed up for those searching on Saturdays and Sundays, so you might be best off just skipping the weekends for fare research anyway.