Airfare Fluctuations: Can a flight price really change 135 times?

So you wanted to go to Florida last August? You freed up your calendar, blocked your dates, and made the commitment to take a family vacation. You decided that you would leave from New York August 11, fly to Miami, and spend seven nights there before coming home.

An In Depth Look at Airfare Fluctuations


The lowest cost flight for your trip would have been $197 per ticket. That is, unless you bought on March 31 when it would have been $247. Or on April 3rd when it would have been $298. Or on April 19 when the lowest fare was $332. Or maybe you waited until May 12; then, the fare would have been $241.

In other words, who the heck knows what your air fare would have been? It would have varied quite a bit depending on the exact date you decided to buy. In fact, over the period between 320 days out and 1 day out, there were 135 different price changes for this trip! That’s one every 2.4 days.

Your best bet would have been to book on December 26, seven and a half months before your trip. That was the date when the $197 fare was available. Your worst move would have been to book the day before; the lowest option then was $479. But even throughout the most popular booking periods of one to three months in advance, there were significant fluctuations, with plenty of days where fares were in the $200 range, and plenty of days when fares were in the $300 range.

What may seem like a fluky example is actually very typical. For the average trip in 2013, the lowest available fare changed 92 times. The average difference between the lowest fare, if you bought on the best day, and the highest fare, if you bought on the worst day, was a whopping $312! So timing really is everything, when it comes to buying flights.

We can write a book on why fares change so much (and we actually wrote a pretty long blog piece, if you’re interested.)  But here is a quick explanation. As you might expect, fares can change because airlines purposefully raise or lower them, or start or end fare sales. That’s only part of the story, though. There is another reason why the lowest available fares fluctuate. It is because various fare categories are constantly becoming sold out or getting re-opened as other travelers buy or cancel seats.


We know, this is where it tends to get confusing.

Airlines will generally offer at least 10 or 15 different prices on every flight that they operate. Delta, for instance, offers 18 different fares in the New York to Miami market, ranging from $113 one way to $723 one way (before taxes)! They have a $113 fare, a $123 fare, a $128 fare, and so on. The other airlines who fly that route offer similar menus of fares, meaning at any point in time there are well over 100 possible prices.

Here’s the important part: the price for a flight at any given moment will vary depending, at least partially, on how booked the flight is. For instance, Delta might say that they will sell the first 20 seats at the $113 fare, the next 20 seats at $123, the next 20 at $128, etc. So as each of these fare “buckets” get filled up, the effective price for another seat on the flight increases. Because there are hundreds of travel sites (not to mention the airlines’ own sites) which all offer the same seats for sale at the same time, at any given moment there are thousands of seats being purchased and each purchase might bump up the fare for the next purchase on the same flight. Although the general trend is for flights to get more expensive as time goes by and more seats are sold, from time to time the airlines will make adjustments and release more seats at the lower buckets. This is why fares sometimes move down, as well as up, even without an explicit fare decrease by the airline.

What does it all mean? Last year we looked at a ton of data and concluded that, on average, the cheapest point in time to buy a domestic flight was 49 days in advance. We’ll be updating that study shortly with more current numbers. But the larger point is the market for airfares is unusual and the prices are extremely volatile. At CheapAir, we don’t set prices; we collect them from the airlines and, using our own fare searching technology, present you with the best available deals at whatever point in time you are searching. To help you save the most, we urge you to start checking fares early for any potential trips you are planning, and check often. Don’t necessarily buy right away, but get familiar with the market – learn what’s a good deal and what’s not. And when you do find a good fare, be ready to buy. As the New York to Miami example above illustrates, those good deals don’t last for very long.

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  1. So I was told to delete previous browsing sessions on flights because they remember what you searched for and you will never get another cheaper flight unless you do so…is that true?

    • Margo, we get this question a lot. We should probably devote a whole blog post to this topic!

      I am not sure where or how this rumor got started, but I can say pretty confidently it’s not true — certainly not on our site and I highly, highly doubt any other sites are doing it either.

      Ultimately, the prices come from the airlines. Before we sell a ticket, we are making a direct query into the airline system to confirm pricing. And when those queries hit the airline, they have no idea who the customer is or what they have searched for in the past. So even if they wanted to manipulate fares in this way, they simply don’t have the technical infrastructure to do so. Although fares changes often, they are always consistent at any moment in time; anyone booking the same flights for the same number of passengers at the exact same second will always pay the same fare.

      It is possible that in rare situations if you make two identical searches within a short period of time the 2nd search might use “cached” results and show the same fares as the first search, even if the price had actually changed. However, before you complete your purchase we and other sites always double-check the fare, so in that scenario you would be alerted to a price change before confirming. In the end, you are always paying the correct, current fare.

  2. I am told by airline employees that fares can be lower than any advertised, and that there are last minute fares that are available because the airplane is nearly empty. Two of these employees are flight attendants on major airlines and have also worked for charter airlines.

    • Dan, it’s true that there are often “unadvertised” sale fares. We’re happy to say that our flight searches will always include those fares. They tend to come and go quickly, which is why we advise customers to check flights frequently. Regarding the last minute fares, we actually looked at this in depth, studying over a billion fare quotes in 2013. We found that great last minute fares have become EXTREMELY rare; flights are just too full. Check this blog, we should have the full study released within the next few weeks.

  3. Is $1595 for a ticket to Paris from Chicago O’Hare a good fare? We area a family of 4 traveling on 6/5/14 and returning 7/4/14. Dates are flexible within 3 days at both ends. Found fare on AA for $1595. We want 4 seats together if possible.

    I saw same tickets for $1300 before Christmas. Seems like they have been at $1595 to $1795 the last few days for a direct non-stop flight which is what we prefer.

    Would love to get that $1300 fare – I had just started looking and didn’t know if that was a good fare or not. What do you think?

    • Hi Chris,

      Since you’re traveling to Paris during the peak summer time and returning around the busy July 4th holiday, you’ll want to book sooner than later. If you can depart and return 1 day earlier, the prices should be closer to $1500 per ticket. I’d recommend purchasing your flights soon. To view flight schedules and book, you can use this link: Remember, when purchasing flights on, you can automatically take advantage of our Price Drop Payback program where if the price for the same flight decreases, we’ll give you a credit for that amount, valid up to $100. Please let us know if you need any help with finding flights.

  4. Does your pricing model include flights to Africa? I’ve been looking at fares to Accra, Ghana for December 2014. Even though it’s 12months away ( I started looking in Jan 2014), the fares are unusually high and do not show any decreases at all.

    • Hi David,

      Unfortunately no. Fares during December tend to be high due to the holidays. I’d recommend to continue to monitor the fares more.

  5. My husband and I are trying to book a flight from Charlotte to St. Martin in May 2014 (preferably around 5/18-5/28…. But we are flexible 3+days either side). Every time I search its the same price $708. When is the best time, or rather, how many days out is the lowest rate offered for international travel. You stated 49 days for domestic only.
    Thank you

    • Hi Tammy,

      For your flights from Charlotte to St. Martin, it looks like it would be cheapest to fly Saturday, May 17 to Tuesday, May 27. The cheapest fares for these dates are starting at around $610 per person, not including any baggage fees that may apply. For international flights, it would be best to book at minimum 12 weeks prior to your departure. So you’ll actually want to purchase your flights sometime soon. To view flight schedules and book, you can use this link: Please let us know if you need any help with finding flights.

  6. Your reply to “Allen” on March 3rd, 2014 references best time to buy international flights but while I could print your answer and attachment, I could not find this international best time answer on your 10 Comments. Can you send me a link I can down load for best international times to buy?

  7. We want to travel to Italy in November and I’ve been tracking all flights since February. When do you suggest for me to buy my tickets? Right know they are very expensive. Thank you

    • Hi Laura,

      That can depend on where you are departing from. Typically, we’ve found that international flights to Europe should be booked at least 150+ days prior to the departure. That’s about 5+ months out, so for flights in November you’ll want to purchase sooner than later. To learn more about international flights and when to book, you can read our latest post here:

  8. Looking into going to Disney world mid sept. When is the best time to book?

    • Hi Nevada,

      That can depend on where you are departing from. Generally speaking, Orlando is a very popular destination and it is recommended to book at minimum 55 days prior to your departure. Please let us know if you need any assistance with finding flights.

  9. When to book to Phoenix Sky have convention to go to. Thursday July 24 thru Sunday July 27th, when should I booK. Been reading all this stuff and am at day 54 right now, should i book this next Tuesday or wait to the next week, was wanting a ticket around 350 and right now they are about 472….thanks for any input you will give. Would be coming from Madison Wi, but am open to any other close airports if quite a bit cheaper

    • Hi Wisconsin2Phoenix,

      In checking the fares from Madison, WI to Phoenix for those dates, fares are starting at around $464 per person, not including any baggage fees that may apply. Since you are traveling from a smaller airport (Madison, WI) and traveling on a Sunday (a popular day), fares will be higher than usual. Generally it is better to book flights from smaller airports like Madison earlier than the advised 54 days. I’d probably suggest booking at around 80 days or more. To view flight schedules and book, you can use this link: Please let us know if you need any help with finding flights.

  10. I am doing a study on the airfare daily fluctuation and I would love to know where I could get the datas you used in the above graph.
    Ideally, I would like to be able to evaluate any airfare for any route for the past 3 years, but of course, any help could be useful.
    Thank you

    • Hi SB,

      Unfortunately our data is not made public. It is used for internal purposes only.

  11. We are going to Alaska on May 16, Phoenix to Anchorage, Anchorage to Fairbanks on May 19, then back from Vancouver to Phx on June 1. I am seeing fares (Alaska Airlines) of about $1060. When do you recommend booking for this flight itinerary?

    • Hi,

      I’d recommend to continue to monitor the fares more. You might even want to try pricing out separate one way flights to see if than is cheaper than purchasing a multi-city flight. Either way, you still have plenty of time to continue to monitor the fares more. I’d suggest aiming to book around the New Year. Keep in mind, when you book on, if the price for the same itinerary goes down any time before your trip, we’ll pay you back the difference in the form of a travel voucher for up to $100 per ticket! Please let us know if you need any help with finding flights.

  12. I’m looking to travel from the Hollywood, fl area to Philadelphia for Christmas. Looking to travel dec. 19, and return shortly after Christmas. My dates are a little flexible, and would like the cheapest rates, but also trying to make it easier for family to pick me up at the airport, which is TNN (princeton, trenton). I’m getting nervous about rates jumping up, due to planes filling up for the holidays…should I book today? Any suggestions?

    • Hi Nicole,

      Booking flights for the holidays now would be a wise move. The holiday season is a peak time for flying and fares will be high and flights will fill up. Booking earlier is the best decision since you can ensure you’ll get what you want. However if are flexible, you can still find great deals out there. Flying from Ft. Lauderdale or Miami would be the closest airport options. If you’re adamant about flying into TNN, then I’d recommend booking now since there’s limited flight options for that route compared to PHL. Feel free to check out our Cheap Flights Holiday Index which will show you the cheapest days to travel during the peak holiday season. Keep in mind, when you book on, if the price for the same itinerary goes down any time before your trip, we’ll pay you back the difference in the form of a travel voucher for up to $100 per ticket! Please let us know if you need any help with finding flights.

  13. I want to book a flight from either Winnipeg, MB or Fargo, ND to Dnver, CO for the end of January. Is this going to be my best time to do that? Dates are Jan 22-25. I haven’t flown in about 12 years… I have no idea what a reasonable price is.

    • Hi Stacey,

      Now’s a great time to be searching for flights. We’re about 4 months out from your departure, so I’d suggest to book your flights sooner than later. Flights from Fargo will be cheaper than Winnipeg. Flights from Fargo are starting at around $195 per person versus $476 per person from Winnipeg. To book flights from Fargo, you can use this link: To book flights from Winnipeg, you can use this link: Keep in mind, when you book on, if the price for the same itinerary goes down any time before your trip, we’ll pay you back the difference in the form of a travel voucher for up to $100 per ticket! Please let us know if you need any help with finding flights.

  14. Hello,

    I have already booked a one-way flight through American Airlines from O’Hare in Chicago to LAX in Los Angeles. Problem is, I realized later that the flight is too early and I won’t be able to get off from work until a bit later. There are later flights and I can still switch reservations even though AA will charge me $200 I believe to change it, however, the kicker is that before when I initially booked all flights that day were in the $100 to $200 range and now when I look the cheapest non-stop is over $500! Any chance if I just stay patient I’ll find it atleast in the $200 to $300 range in the coming weeks?

    • Hi Shaan,

      Unfortunately that would depend on when you are departing. Whenever you change your flight, the airline will charge a penalty to make the change plus any applicable difference in airfare based on the current rate for that flight. So if you’re leaving soon, then you’ll have to bit the bullet and make the change. Otherwise, if you have several months, then you could continue to monitor the fares more… but ultimately in order to make a change, you’ll have to pay the fees plus the different.

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