UPDATE: For the latest research on the Best Time to Buy Flights, visit our newest domestic airfare study.

The travel landscape in 2021 looks very different than it did just a year ago. We’ve undergone a huge global trauma, but as we come out on the other end, people are looking forward to flying again.

CheapAir.com 2021 annual airfare study

When you’re ready, CheapAir.com is here to help simplify the process of buying airline tickets. We’ve taken a confusing subject, unpacked it and made airfare transparent. You don’t have to feel stymied by convoluted pricing structures, what comes with your ticket and what is considered an add-on, or which bags can be brought free of charge. CheapAir provides clear insights into the best time to buy an airline ticket.

First up – domestic flights!

This year, we’ve analyzed more than 917 million domestic airfares in 8,000 markets across the United States.* Our mission? To deliver you insights and advice so you can make an informed choice when buying flights.

The study includes:

– The best day to buy a flight, on average;
– The “CheapAir Prime Booking Window” breakdown – the range of dates when you’re most likely to capture a deal;
– Which Booking “Zone” is best for your purchase;
– Which days of the week to fly based on price;
– The best and worst months to buy;
– How seasonality affects airfare prices

Based on data over the last 12 months, we found the “best day” to buy airfare is 64 days out from your travel date. This is an average finding, which means that your particular itinerary’s lowest price might not fall exactly on the 64th day.

The good news is that there is a range of days for every flight itinerary, from the publish date (about 11 months out) to the very last minute that will give you specific benefits and risks. We’ve broken these dates out and call them booking zones.

Booking Zones

Cheapair.com when to buy airfare study 2021 booking zones

First Dibs

315 to 202 days in advance

Approximately 10 to 6.5 months

Every booking zone has its perks, and the main benefit to booking this early is the wide open range of options at your fingertips. The First Dibs zone gives you the most choice in seats, specific flight times, and even classes of service. If you choose to be the early bird, you’ll spend right around $90 more on average than if you wait to buy in the “Prime Booking Window.” Consider it a small price to pay to guarantee the full range of choices.

Peace of Mind

201 to 96 days in advance

Approximately 6.5 to 3 months

The Peace of Mind zone is for you if you prefer to walk the line between choice and value. It’s early enough to keep a nice range of available options, while it’s not quite as expensive as First Dibs. You’ll save about $37 on average if you wait a little longer to buy.

CheapAir’s Prime Booking Window

95 to 21 days in advance

Approximately 3 months to 3 weeks

Most people want to buy in this zone, since most of us have budget as our main factor for purchasing flights. The Prime Booking Window is where you want to be if budget takes precedence in your decision-making. Every year, this booking zone consistently yields the lowest prices for travelers (within 5% of the lowest ticket price). You’re probably going to trade in some of that choice we mentioned earlier, but if cost is the main consideration, this is where you want to buy.

Push Your Luck

20 to 14 days in advance

Approximately 3 – 2 weeks

Once you get into the next zone, you’re starting to – well – push your luck. Inside of 3 weeks, the odds are prices are going to go up, and choice gets limited quickly. This is a zone best left to gamblers. Sometimes you can find a great deal in the Push Your Luck zone, but it’s far from a sure thing.

Playing with Fire

13 to 8 days in advance

Approximately 2 – 1 week

If you wait to buy this close to your flight you’re almost certainly going to pay more, but still about $86 less (on average) than if you wait until the very last minute. If you’re the kind of person who likes to live life on the edge, you might like the Playing with Fire zone. Proceed with a lot of caution.

Hail Mary

7 to 0 days in advance

Less than a week

Let’s face it. Very few people choose to buy in the most expensive zone. It’s the zone where people find themselves out of necessity (family emergency or unexpected trip), rather than a premeditated choice. If you have to do so, you’ll likely pay about $160 more than you would if you shopped in the Prime Booking Window. If you do find yourself here, we can help. CheapAir offers monthly payments for customers if the cost is prohibitive.

Days of the Week Data

This may not be what you read on the Internet, but did you know there’s little to no effect on price depending on what day you buy your ticket? In fact, the average low fare only varies by about $1, no matter the day of the week.

cheapair when to buy study 2021 weekly

You should pay attention to the day you choose to fly, however. Mid-week flights (Tuesday and Wednesday) almost always offer the best value and choice most of the time while the weekends will cost more and choice can be limited. You can expect to spend (on average) about $82 more to fly on a Sunday, for example, than on either Tuesday or Wednesday. It might not seem like a big difference for one ticket, but if you’re shopping for a family of 4 that’s a savings of almost $330!

Best (and Worst) Months to Buy

Some years there are greater differences between the months. This year there isn’t as much (about $100 separates the most expensive from the least expensive month). That’s good news for travelers.

cheapair when to buy study 2021 weekly

The most expensive month to fly is actually March this year, but other than that news (which is likely due to a combination of spring break and COVID-19), summer and the holiday travel in November/December are projected to be the priciest. The fall months are a great value if you set aside November, and winter is as well (if you set aside December). Summer Summer is a bit of a wild card this year, with travel projections showing great value there as well.

Seasonality Insights

Depending on the season, you’ll want to adjust the time frame you buy. Here’s a quick snapshot to help with planning:

cheapair when to buy seasonality

Here’s the Highlights

Whew! That’s a lot to take in. Here’s a brief summary of the key points you need to make an informed decision.

The earlier you buy will give you the most choice but cost a bit more, while waiting until you’re about to travel means you can expect to pay a lot more for a more limited set of flight options across the board.

Many travelers will land somewhere in the middle – hopefully in the Prime Booking Window- where you get the best-priced tickets with some choice still on the menu.

CheapAir is committed to being a better choice for travelers. We offer a smarter flight search to give you a simple breakdown of each ticket. You can also compare flights across classes of service and across airlines.

See what we’ve uncovered as part of our International Flight Report.



  1. I bought my tickets way early and got a great deal. By the time the date came my original flight was canceled. I lost my seat selections I paid extra for and had to pay for specific seats on new flight that had a 61/2 hr layover. My original flight had a 45 minute layover. So boo 👎 for buying tickets that far in advance.

    • Jennifer, Sorry that happened to you! Unfortunately, that is one of the possible trade-offs with buying too early. Usually, it is rare, but this past year, airlines have adjusted their schedule a bit more than usual as they adjust to travel demand and staffing shortages. If you booked it with us, we will always alert you to any changes via email. As soon as you see a change feel free to reach out to us and we will do our best to work with the airline to reprotect you to similar flights with similar amenities.

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