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. We are looking to go to Hawaii in March. We have 26 people going with us. We have looked for group rates and they are much much higher than just buying tickets 4-6 at a time…. why so? Wouldn’t they give a break to someone buying 26 tickets? Options ? Suggestions??

    • Hi Brady, If you’d like to call our main line at 1-800-CHEAPAIR and then press x1167, our Senior Travel Advisor Glen, might be able to help you out. I’m not sure if you tried to find 26 tickets online or if the groups desk at your airline is pricing out higher? You should reach out directly to the airlines if you haven’t already. They would have group pricing to beat anything we could offer.

  2. I’ve found that if i search several sights at the same time, and if i dont book immediately that the fare goes up. I was looking to book a flight that started at $220, and as i searched it went up $55. I have heard that there is a algorithm that as you search it increases. This was for a domestic fight that was 7 months ahead of time. This seems to be a scam, i am sure that the prices dont fluctuate $55 in 2 or 3 hours. You cannot tell me that the price went up that much from the time i filled out the form to submitting it.

  3. Hi!
    We are looking to book a trip to Montego Bay, Jamaica around Christmas (12/21 – 12/30). There is a one way flight (we were thinking of doing 2 – one way’s) on Sun Country for around $520, but I have never heard of this airline and the little bit of research I did, had pretty bad reviews. There is another flight that is around $700…So, trying to figure out if it’s worth it so spend the extra $, to go with a more reliable airline. We haven’t even started looking at returning flights yet 😮 And advice? Thanks!


    • Hi Amy, Sun Country has been around for close to 40 years. It’s not one of the larger airlines, and it doesn’t offer some of the amenities of the legacy airlines, but it’s a solid choice. Of course, when flying these days, there’s not a lot of frills and travel can be stressful. So for your peace of mind, if you are more comfortable going with an airline you feel more comfortable with, we say do that!

  4. want to book flights for myself and 2 teenage grandsons from Tucson to Washington DC for spring break during the middle of March. Any ideas?

    • Hello, that sounds like a great plan! For the best prices, plan to search the Washington metro area. There are 3 airports that service Washington, DC. Baltimore (BWI) often offers lower prices for leisure travelers. Also, the prices from Phoenix may be a lot better than from Tucson. You should weigh convenience and cost. DC is a great vacation idea and is full of bargains. Many of the top sites and all of the Smithsonian are 100% free. Good luck to you!

  5. When is the best time to buy a flight in the 0 – 21 days range?
    I usually can’t purchase my flights 21+ days in advance.

    Thanks in advance for your time!

  6. Hi!
    I would like to know the July – Dec 2015 historical data and predicted price trends for flights from the US (Chicago) to Asia (Taiwan). I prefer the information be presented in a graph similar to the one used in the article, if possible. Please let me know where I can find this information. I am flying to Taiwan the week of Jan 5th, pending flight prices. Any assistance in finding cheap, one-way flights for two between now and then would be greatly appreciated. Thank you!

    • Hi Grace, We generally do a study with results posted on our blog in February. This isn’t information we send out in graph form by request. Apologies. I can tell you that we recommend travelers buy tickets to Asia almost 10 months out from their travel dates – so if you are traveling in January you need to purchase sooner rather than later (the best airfares are long gone by now). But one general rule that we tell everyone who has this question is to research flights early and often. If you see flight prices start to climb, this is an indicator that it is a good time to buy. Once the airline sells the limited number of seats at a certain price point, they bump prices to the next level (and so on). An incremental increase in flight cost generally will indicate that the flight is selling, and that prices will not subsequently go down. The opposite scenario is also important. If you watch flights for 4 weeks with no movement in price and then all of a sudden the fares go down? That means it is time to buy. The flight was likely not selling at the previous fare so the airline put it on “sale.” The one caveat if you find yourself in this situation – do not wait. There are likely dozens if not hundreds of people in your situation and some of them will take advantage of the low fare. It will not last. One final caveat – if you see a good itinerary (good connections or nonstop) at a good price, hop on it as well. Nonstops are a premium. The longer you wait to buy, the less availability for those good trips. So you might save money by waiting, but you could also get stuck with a much less desirable itinerary. I hope this helps! Good luck to you.

  7. 2 of us are looking to travel to Athens-Greece from Washington DC around 7/21 to 8/2 with a little bit of flexibility on each end. Last week Turkish Airlines and Air France had prices ranging from $840 to $950 for reasonable flights (1 stop, less than 16 hour each way). After getting my time off approved I went to book this week and prices had increased to a minimum of $1420. Any idea why there was such a quick jump and how long to wait to see if prices come back down?

    • Hi Dan, If we can assume that all of the variables are exactly the same as when you previously searched, the likely scenario is that the lower fares simply sold out. I do know Turkish Air and Air France were offering great deals all over Europe for the past couple of weeks. When there are great deals on offer, they go quickly. At any given time, lots of people are searching. I wouldn’t wait long. Maybe give it a week or two at most and watch to see if the prices continue to rise incrementally. If they do – even by $10 or $20 bucks, that is an indication that the flights are selling down through each fare class. Because Turkish Air was offering some pretty aggressive sale prices, it’s not completely out of the realm of possibility that they might do it again. However, don’t bank on that. Our recommendations are to buy tickets to Europe about 9 months out for the best price. And you’re already at that threshold now.

  8. We are planning a trip to Orlando from Minneapolis May 2-7, 2016, 2 adults & 3 children. I have been checking prices daily for a while now and the price of a nonstop roundtrip ticket through Delta was about $384/ticket. I checked yesterday & today and all of a sudden the price for the same exact flight is about $1,100/ticket! Why would there be such a huge jump in price all of a sudden? An increase of $715/ticket seems a little extreme! Do I wait it out and hope for the price to come back down to the original $384 or should I start looking at other airlines/options? I chose Delta because they are the only one that offers nonstop flights to Orlando from Minneapolis. I would rather not do connecting flights when we’re traveling with 3 young children who have never flown before.

    • Hi Calla, You are right – that does seem pretty extreme! There are a few things going on right now that could be affecting the fare. There are some pretty crazy airfare wars going on so I think we can probably assume that this is not an availability issue, but rather the airlines jockeying for position. It’s too early to buy and I think $1,100 to Minneapolis from Orlando is quite high. Keep monitoring for a few weeks – I think things will smooth out and you will probably see prices come way back down. We generally advise you buy domestic fares about 47 days prior to travel (on average). So – waiting a few weeks (at least until fall when the airlines tend to put out their early bird fares for spring and summer) would probably be prudent. Good luck to you.

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