UPDATE: For the latest research on the Best Time to Buy Flights, visit our new airfare study: The Best Time to Buy Flights in 2022.

You may have noticed that airfares change all the time. Exhausting. To alleviate the pain, we conducted a huge airfare study, and have boiled down the insights for you – to help you get a cheaper airfare!

In CheapAir.com’s 2017 Annual Airfare Study, we crunched 921 million air fares, and found that the lowest fare for a given trip changed on average 71 times. That’s about once every 4½ days! And with each change the lowest price went up or down by an average of $33. So, clearly, it matters a huge deal when you choose to pull the trigger on your flight purchase.

cheapair when to buy 2017

For the second straight year, our study concluded that for flights within the continental U.S., 54 days in advance was the best time to buy, on average. Flights to Canada were similar, but for Hawaii, the Caribbean, and international destinations the optimal lead times were generally higher (99 days in advance to Europe, for instance).

Like always, though, we caution that these are just average numbers. We looked at 2,934,098 individual trips, meaning flights from a Point A to a Point B departing on a specific set of dates. Across all 2.9 million trips, the actual best time to book varied wildly depending on the market, travel dates, and the specific travel preferences/must-haves of the traveler in question. As a result, we don’t recommend you get too caught up in trying to book on any one specific day. Rather, we like to focus on a range of days, which we call the “prime booking window” where for most trips the best time to buy usually falls. For domestic fares, the prime booking window is between 21 and 105 days in advance.

The 5 Booking Zones

Expanding on that concept, we’ve divided the entire window of time when a flight can be booked into 5 booking zones:

cheapair 2017 when to buy booking zones

First Dibs
178-321 Days in Advance
(approximately 6 – 11 months)

When you plan to book as early as possible, in what we call the “First Dibs” zone (178-321 days from travel), you can expect to pay a premium for airfare (about $50 more on average) and will most likely see that airfare price decrease at some point in the future. The airlines set their published fares at around 11 months from travel dates and build in the flexibility to lower the fares as they get a better idea of demand. The benefit to you for buying this early is a full choice of flight options. You can pretty much tailor your itinerary to your specifications. Nonstop needed? No problem. Seat selection is plentiful and you also have your pick of available flight times. For a price, of course.

Peace of Mind
106-177 Days in Advance
(approximately 3½ – 6 months)

Maybe you’re looking for a bit of stress relief and a lower premium. In that case, you should try the “Peace of Mind” zone (106-177 days from travel). The “Peace of Mind” zone is perfect for a traveler willing to spend a small premium (around $20 more on average) to lock down the best fare for specific dates. At 3.5 to 6 months out, you’ll still have options to choose from that decrease closer to travel dates.

Prime Booking Window
21-105 Days in Advance
(approximately 3 weeks – 3½ months)

Now, we’re to our fave booking zone, the aforementioned “Prime Booking Window”, occurring 3 weeks to 3.5 months in advance. This zone is where the cheap airfare hunter wants to concentrate his or her best bargain-shopping efforts. Keep in mind that fares will still fluctuate within this rather large window, but in general, the sweet spot is in this zone – where the best fare tends to pop up and fares tend to be within 5% of their lowest.

Push Your Luck
14-20 Days in Advance (2 – 3 weeks)
If you miss the “Prime Booking Window,” your next available option is the “Push Your Luck” zone (2 to 3 weeks from travel dates), a relatively small window of time where gamblers will feel at home. Most of the time, fares will continue to rise and flights can be full. But here and there you might catch a lucky break and find there are actually some comparatively low fares from months ago that have stuck around. If you’re thinking of rolling the dice, be smart about it. Popular destinations in high season are not a great gamble for last minute deals. But if you’re going to a less popular gateway or traveling low season in a popular town, you might be pleasantly surprised.

Hail Mary
0-13 Days in Advance (less than 2 weeks)
Last-minute fares (anything inside two weeks) we consider the “Hail Mary” zone. If it isn’t already obvious, the Hail Mary zone is so-named because the overwhelming majority of last minute airfare searches end in a major outlay of cash (on average $150 more than buying during the “Prime Booking” window). And again, this close to travel your choices are limited. The best itineraries are often sold out or only have a limited number of seats – the most expensive ones – still available. Not ideal. Finally, everyone should know the absolute worst day to buy a flight is the day before you need to travel. If you wait until then, you can expect to spend $249 more on average with the least number of options. Ouch!

In many cases, the best time to buy will vary depending on the time of year you are traveling, so we also looked at the best time to buy specifically for the spring, summer, fall and winter seasons.

The “Seasonality Effect” – Adjust When You Buy Depending on the Time of Year


When to Buy Summer Flights

Many Americans take their one “big trip” of the year during the summer months. Because demand is higher, you’ll want to approach summer travel research and airline ticket purchase a bit more aggressively (hint, hint: don’t wait too long). Here are a few tips to help you score a sweet price on a summer airline ticket (or 3!)

  • Buy a little earlier. The average best time to buy is 76 days, or about 2.5 months in advance.
  • Prime Booking Window is 21 – 140 days from travel. In this pricey season, one positive is that the Prime Booking Window starts earlier than in other seasons and you can still get good fares later in the season if you are willing to be flexible with airlines, flight times and number of connections.
  • The difference between the best and worst priced days is a whopping $250!
  • Our summer airfare calendar can help make the shopping process simple and easy – showing you the cheapest and most expensive dates to fly.

When to Buy Flights in the Fall

You have a little extra time to consider your flight plans if you’re traveling in the fall. In addition, fall is an overall good value for leisure travel. The one exception is Thanksgiving week travel, when airfares are at a premium and tend to sell out quickly. Purchase Thanksgiving airfare on the early side for the best prices.

  • If you’re traveling in the fall, you can probably wait a bit longer to book air tickets. The best time to buy is 47 days out, about 7 weeks in advance.
  • Prime Booking Window is 21 – 91 days from travel.
  • No surprises here – the worst time to buy your airline ticket in the fall is the week before you’re traveling. If you wait until the day before your trip, you can expect to fork over a painful $270 more than the best priced day.

When to Buy Winter Flights

Other than the peak holiday travel dates around Christmas and New Years, winter can be a great time to get a good deal. (We will cover the holidays in another post.) For general winter travel:

  • 54 days from your expected travel date is the best time to buy an affordable airline ticket in the winter months.
  • Prime Booking Window is 21 – 86 days from travel.
  • The difference between the best and worst priced day is $275

When to Buy Spring Flights

Springtime is a bit tricky. On the one hand, there are no major travel holidays to drive up prices on specific dates. On the other hand, “spring break” dates cover March through April and inspire travel from college students and families with kids alike. So, in general, planning ahead is key for snagging better prices.

  • 2.5 months (75 days) from your travel date is the optimal time to buy airfare for spring air travel.
  • Prime Booking Window is 21 – 105 days from travel. Because you have a larger window to get the best fares, buying early is not a gamble.
  • The difference between the best and worst priced day is a (relatively moderate) $224. If you tend to procrastinate, you’ll come out better financially in the spring months.

Additional Consideration: The Cheapest Days

One more factor to consider before you buy – the day of the week. Here we need to distinguish between two different, but sometimes confused, topics. The day of week you buy a flight, and the day of week you fly. These are different topics with different statistics and conclusions.

The Cheapest Day of Week to Buy an Airline Ticket

An age-old question (well, Internet age-old, anyway): Will I get a better fare if I buy my ticket on Tuesday, Wednesday or any other day of the week? Our data shows that, on average, the answer is no. Will you sometimes find a deal on a Tuesday? Yes. But you are just as likely to find a deal any other day of the week. To cite some numbers here, the average lowest fares by purchase day of week are all within $2. That’s less than a 0.6% difference.

The Cheapest Day of Week to Fly

Now, if you ask us whether it is best to travel on one day of the week or another to get the best airfare, that is another story. Tuesday and Wednesday are the cheapest days to fly. Sunday is the most expensive. Flying on a Tuesday or Wednesday will save you an average of $73/per ticket.

A Few Takeaways

Whew! That’s a lot of information, CheapAir.com. We hear you. It’s a complicated air travel world out there, but here’s the thing. If you take away any helpful little nuggets of information from this study, we ask that you remember these two:

First, fares change frequently. Like, a lot. Even though the law of averages can give us a tidy little number like “54 days from travel is the best day to buy,” the day-to-day fares are much more volatile. When you get serious about an itinerary, be ready to buy quickly when you see a good fare. This tactic will assure you a good shot at capturing a very good fare, if not the best airfare for a particular flight.

Second, and most importantly, when you buy is key. Purchasing during the “Prime Booking Window” can give you a clear edge and maximize your chances of scoring one of those elusive “best airfares” everyone is eager to scoop up. If we’ve piqued your interest, you can check out our newfangled, first-of-its-kind Best Time to Buy Flights tool to search on your specific destination and get custom advice from our airfare intelligence data.



    • Hi Jeyla,

      We’re sorry you’re having trouble booking. What is the problem you are having? Any detail you can provide is helpful. Separately, if you’d prefer you can call us and book with a Travel Advisor at 1-800-243-2724 and we’d be happy to assist you.

  1. Thank you for sharing the post and enlightening the best time to buy cheap tickets for the flight. I am travelling from Chicago to Florida next month and I got the best deal by following your words. I had a great experience. Thank you guys for sharing this post!

    • Thanks so much for the positive feedback, Ashley! We love to hear about positive experiences travelers have with our advice.

  2. Hi,
    I am looking for flights for two from IAH to ATL. 2 weeks ago the deals were awesome at $135 round trip. For the past week the prices were stuck at $230’s to 250’s. I am waiting one more day since tomorrow is Tuesday and fare sale theoretically should come out tonight and be matched tomorrow. Do you think this is a good idea?

    • Hi Xavier, It is true that sales do come out on Tuesday! Jump on the fares soon if you don’t see a good sale fare though. Since you have seen the fares start to climb, it’s not likely that they’ll drop again.

  3. hello, I am looking for 4 tickets flying from San Francisco (or any near by airports: San Jose or Oakland) to FLL (Florida), from August 2 to Aug 12. We are +/- 1 day flexible on departure day and on the return we need flight after 11am as we will be taking a cruise. I saw the price around $370 round trip about in Jan and February but the price has been to 440+ now. Should I wait according to the prime booking window or booking it now
    Thank you!

    • Hi Isabel, I would book sooner rather than later. The prime booking window is based on averages for purchase and not specific itineraries. If you have been watching this fare for a while and see that the price has crept up it will likely continue to inch upwards. That just means people are buying the lower priced fares. And because you are booking flights to coincide with a cruise, there are others also likely shopping your itinerary. Buy soon.

  4. When is the best time to buy airline tickets to Sydney Australia from LA? We’re boarding a ship out of Sydney just before Christmas 2018. Thanks

    • Hi D. It’s going to be best if you buy tickets as soon as they are available as you’re looking to travel just before Christmas. That’s quite a busy (and expensive) time to fly.

    • Last year we recommended buying flights to Africa about 120 days out for the best prices, on average. We’re still crunching data for 2018, but based on your travel dates you should probably start at least a preliminary search right now. You’re going at the tail end of the rainy season, so you might see some reasonable fares.

  5. Are the best times to buy in every season specific to domestic flights as well, or do they include international flights?

  6. I’m looking for a cheap flight from Minneapolis to Dallas on Nov. 22 – 26 or 27, when is the best time to look and buy

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