The Science Behind Airfare—Unraveling the Mystery of the Skies

float plane juneau alaska

As some of you may know, I am a scientist among other things. Scientists tend to have very analytical, everything-happens-for-a-reason-and-I-need-to-know-the-reason mindsets. Years ago, Isaac and I spent the good part of a solid week trying to book tickets to South America. We would type in our multi-destination and a price would appear, but as soon as we would click ‘buy now’ the price was up by $5000! This went on for days until Isaac pulled an all-nighter and finally was able to nail down our tickets for the price that allowed us to go. This experience influenced me to step outside of the Travelocity box and decipher the science behind ticket prices.

Float Plane, Poison Cove, Alaska

Float Plane, Poison Cove, Alaska

A quick Google search will tell you that the cheapest days to fly are Tuesdays, Wednesdays and Saturdays. This is true because most people don't want to fly on these days, especially the business crowd or the long-weekend vacationer. In my experience, Tuesdays have always been the cheapest days to fly, with Fridays and Sundays being the more expensive days to fly if it is a no-holiday-month. Note—all bets are off in December, Christmas derails the regular system. Your best bet around large holidays is to fly on them.

So, the magic fly date? Tuesday. Tuesday is special not only to fly on, but also to book your ticket on. Yes, the day you book your ticket matters. The fateful all-nighter happened to be a Tuesday, and I later found out why:

  • Airlines sales post late Monday, but it isn’t until Tuesday that sales are announced.
  • Airlines start matching their competitors' sale prices on Tuesday morning
  • By 3 p.m. ET Tuesday, this matching activity is complete and shoppers see the lowest prices from all the airlines.

Airfare sales can last through Wednesday and even Thursday. Sometimes purchasing on a Wednesday is the cheapest because come midnight Tuesday, the sale airfares that were not purchased show back up on the computers system.

So, aside from Tuesday, what other tricks do I have up my sleeve? Lots!

The first step is to determine which category you ft into:

A. I live in a metropolitan area and there is major airport that I am going to fly out of

B. I do not live in a metropolitan area and I will drive to a major airport within the region or I will fly from a small local airport to a major airport to then fly out of

Depending on which category you fall into above, the following points may or may not apply to you.

  1. Research your destination airport, you will be able to see which airline carriers service the airport you are trying to reach, match those airline carriers with ones that frequently service the airport you are trying to leave from, and then you can check that airline carrier’s website directly. If you do not live in a metropolitan area, this is important for you. For example, I live in S.W. Colorado, where there are no major airports. My closest major airports are Albuquerque, Denver, Phoenix and Salt Lake City, so I need to do some research before I decide which one of the major airports to fly from. For example, finding out that Iceland Air flys into Denver direct from Reykjavík makes a flight from Denver cheaper than if I were to fly from Albuquerque or Salt Lake City, which would route through Denver anyway.
  2. Research airport hubs around you, some international airports receive more airline carriers than others, which creates competition and drives the prices into/out of that airport down.
  3. Do an internet search to find out what airlines are hubbed out of which airports. NOTE: This is different than airlines servicing an airport. For example United Airlines hubs out of O'Hare and Houston, but they service flights around the world, therefore if you were to fly United out of O'Hare it will likely be cheaper than flying another carrier that does not hub out of O'Hare.
  4. Research smaller airports in the area. Often, budget or Low Cost Carrier airlines do not fly into major hubs. For example, Allegiant Air charters low cost flights from Mesa, AZ, near Phoenix, to many U.S. cities, but they do not fly into Phoenix.
  5. Low cost carrier airlines, like Allegiant, Spirit or Southwest, often do not show up on search engines like Travelocity or Expedia, so you will need search their websites directly.
  6. Do an Expedia or Travelocity search and you will be able to see what flights are routed automatically though which cities. It’s often cheaper to fly into the cornerstone airport and then take a train or bus to your actual destination. For example, Milan receives flights from the U.S. more than any other Western European airport aside from London, so I will often fly to Milan and take a train the rest of the way to my destination.
  7. Low Cost Carriers are not always the cheapest option. Legacy or “major” airlines like US airways, American Airlines, British Airways or any of the larger carriers will often post sales to fill up flights, and if you don’t mind sitting in the middle seat, its an easy way to snatch up a cheapie.
  8. One ways can be cheaper than round trips. I will often book one ways, even on different airlines if I have noticed that an airline is running a deal for my departure date but not for the return date. I have flown Southwest out of Portland to Oakland and Frontier from Oakland to Portland.
  9. If you are moving around while you travel, consider a multi-destination ticket or piecing together one ways with train or bus travel.
  10. Note: Round the World tickets (RTW) are rarely cheaper than piecing it together creatively, and lets be honest, who wants to lock themselves in?

FACT: Flexibility will ALWAYS yield the cheapest ticket. Don’t request your days off work until you have found the plane ticket you want.

Looking through the window of a float plane near Juneau, Alaska

Looking through the window of a float plane near Juneau, Alaska

FACT: Airline tickets are not cheaper earlier. Unless you are planning to travel around a high-traffic holiday like Christmas or Thanksgiving, the cheapest prices are not booked well in advance. Most airline computers are not even programmed to compute for sales more than 45-60 days in advance.

Lastly, I have noticed that airline search engines will track my traffic, dates and potential airports, and increase prices after I have been searching on the same computer for a while. There is no scientific evidence for this, but I like to search for my tickets on a different computer or IP address than the one I actually book my tickets on. I usually just write down the flight numbers I want when I have found them and then book from a separate location or device. This explains the massive price increase Isaac and I were seeing when we would try to book tickets to South America. Since that time, I have noticed it again and again.  It is the same targeting you see when ads on your Facebook are tailored to your specific likes and internet searches.

Skyscanner app screenshot showing the variance of price per day

Skyscanner app screenshot showing the variance of price per day

Search Engines and Apps that I use:

SkyScanner app – An invaluable app, allows you to search in ways that other engines do not. You can search from your departure airport to ‘everywhere’ on ‘any date’ and the results will show you the least expensive options. This is helpful when you are in Europe or SE Asia and you want a last minute cheap flight for the weekend, but you don’t really care where. I have found next-day 20 Euro RT flights from Milan to Budapest this way. At that price, why not? You can also conduct regular searches on SkyScanner. The graph feature will show you what days are the least expensive to fly on—pretty cool!

OneTravel – Although most search engines receive the same general flight information from airline carriers, OneTravel seems to always be the cheapest. Part of the reason for this is that One Travel searches smaller airports as well as hubs. My husband recently found a flight from Santa Fe, NM to Manila for $800 RT! One Travel also has great customer service.

Example of Travel Zoo top 20 deal

Example of Travel Zoo top 20 deal

Travelocity – The site is sometimes finicky, but I have used it a lot and it has got the job done.

TravelZoo - Signing up for their 'top 20' email list will automatically send some great travel deals to your inbox.


Budget Airlines that have deals in the Americas, Europe, and Parts of Asia: 

[see photos below for the route map, or click the 'route map' link to redirect to the carrier's website]

Allegiant Air: A low cost carrier with hubs in the west and in Florida. Allegiant flys to some off the beaten track towns. Allegiant route map

Southwest: Southwest flys to many hub cities in the US, Mexico, and the Caribbean. Southwest flights can only be booked on their website. Southwest route map

Spirit: A low cost carrier that has hubs in CA and FL. Flys to and from many US cities to central America, Mexico, and as far as Lima, Perú. Spirit route map.

Frontier: Often runs many specials, I have seen one-way flights as low as $15! This airline will show up on a search engines and does fly into hubs. Frontier route map

Ryan Air: LLC that services most of Western Europe, as well as parts of Eastern Europe. Ryan Air route map

Easy Jet: Services many of the same places as Ryan air. I have flown Easy Jet many times and found flights within Europe as low as 10 Euros for a 1 way! Easy Jet route map

Norwegian Air: Flys to 38 countries, including Bangkok, New York City and Dubai. Flights from NYC to London can be as low as $250 1 way! Norwegian route map


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